Name: preparation of polyoxometalate-based photo-responsive membranes for the photo-activation of manganese oxide catalysts
Uploaded: 2018-08-07T14:30:00.000+00:00
Duration: 5 min 47 s
Description: Watch this Scientific Journal Video about Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts at JoVE.com

a.y. 获得了东京大学机械系统创新项目全球卓越中心的财政支持, 并得到了东京大学博士学位研究的东京都补助金。这项工作部分是由 jsp KAKENHI 资助的青年科学家 (B) (17K17718) 所支持的。

在使用化学品之前, 最好参考所有相关的材料安全数据表 (MSDS), 因为这些合成中的一些使用是高酸性和腐蚀性的。此外, 在这项工作中使用的一种聚合物 (聚丙烯酰胺) 可能含有致癌单体, 丙烯酰胺。使用个人防护设备 (安全眼镜, 手套, 实验室大衣, 全长长裤, 闭合脚趾鞋), 以防止伤害化学品或热。在进行交联过程后, 应将膜样品储存在黑暗条件下的水中, 以避免干燥和任何不必要的光化学反应的发生。
1. 聚甲醛/高分子复合膜的制备
注: 合成程序如下, 在文章中报告的海伦等。14, 除了 POM 的数量被改变。
<ol><li>前体聚乙烯醇 (PVA) 溶液的制备<ol>
<li>添加3克聚乙烯醇 1000 (完全水解) 和搅拌棒到50毫升瓶。</li>
		<li>给瓶子加27毫升水。</li>
		<li>在搅拌条件下, 将瓶子加热到70摄氏度, 以完全溶解所有聚乙烯醇微粒。</li>
	</ol>
</li>
	<li>前体聚丙烯酰胺 (PAM) 溶液的制备<ol>
<li>添加0.75 克聚丙烯酰胺 (见材料表) 和搅拌棒到50毫升瓶。</li>
		<li>给瓶子加29.25 毫升水。</li>
		<li>在搅拌条件下, 将瓶子加热到70摄氏度, 以完全溶解所有聚丙烯酰胺颗粒。</li>
	</ol>
</li>
	<li>聚甲醛和高分子混合物溶液的制备<ol>
<li>将2毫升 PVA 溶液和2毫升 PAM 溶液添加到50毫升瓶中。 注: 由于这些聚合物溶液具有高 viscocities, 所以准确测量其体积是必不可少的。</li>
		<li>添加一个三角形的搅拌杆和1克的 H3密码12O40到瓶子。 注意: H3密码12O40是一种高度酸性的材料, 应该储存在冰箱里。当使用它时, 用塑料材料而不是金属的。</li>
		<li>在剧烈搅拌条件下, 在水浴中加热瓶至70摄氏度, 在浸出70摄氏度后继续搅拌6小时。</li>
		<li>将玻璃衬底 (5 x 5 厘米2) 放在热板上 (约100°c), 并将溶液滴 750 ul 置于基体上。 注: 在滴入过程中应保持热解, 防止聚合物凝。</li>
		<li>要使样品干燥, 请在室温下将其保持在黑暗状态下过夜。</li>
	</ol>
</li>
	<li>膜样品交联工艺<ol>
<li>添加72毫升蒸馏水, 24 毫升丙酮, 2 毫升25% 戊二醛溶液, 和2毫升 HCl 到100毫升瓶。这种混合物称为交联试剂。</li>
		<li>把玻璃基体与样品在培养皿 (大约9.5 厘米直径) 和添加交联试剂, 直到膜完全浸入。</li>
		<li>30分钟后, 用蒸馏水代替交联溶液, 清洗一次。</li>
		<li>使用刮刀将膜从玻璃基板上剥离, 并将其贮存在冷水中。这种聚甲醛/高分子膜称为 pom/聚乙烯醇/PAM。 注: 如果膜用于下一过程 (与供方金属或 MnOx沉积反应), 则应省略剥离过程。</li>
		<li>利用聚甲醛/聚乙烯醇/PAM 的显微拉曼光谱和红外光谱测定膜13的化学结构。采用与参考相同的方法制备的聚乙烯醇/PAM (缺乏 POM) 样品的 FT 红外光谱。</li>
	</ol>
</li>
</ol>2. 聚甲醛/高分子膜与供体金属的反应 (Ce3 +和 Co2 +)
<ol><li>Ce3 +解决方案的准备工作。<ol>
<li>添加2.08 克 Ce (NO3)3 · 6H2O 和搅拌杆到50毫升瓶。</li>
		<li>将30毫升的水添加到瓶子中, 搅拌溶解所有 Ce (NO3)3。</li>
	</ol>
</li>
	<li>膜样品与 Ce3 +的反应<ol>
<li>将膜样品放入培养皿中 (大约9.5 厘米直径), 加入 Ce3 +溶液, 直到膜完全浸入。</li>
		<li>将培养皿放入预加热的烤箱中, 温度为80摄氏度, 为5小时。</li>
		<li>用蒸馏水代替 Ce3 +溶液, 清洗一次。</li>
		<li>储存在蒸馏水在黑暗的条件。</li>
	</ol>
</li>
	<li>Co2 +溶液的制备<ol>
<li>使用与 ce3 +相同的准备和反应程序, 除了使用1.14 克 CoCl2· 6H2O 而不是 ce (3)3 · 6H2o. 样品与 ce3 +和 Co2 +的反应是分别被称为 pom/聚乙烯醇/pam/Ce 和 pom/聚乙烯醇/pam/Co。</li>
		<li>研究了聚甲醛/聚乙烯醇/聚丙烯酰胺/铈和 pom/聚乙烯醇/pam/Co 的显微拉曼光谱, 以确定12O403-后的分子结构与供体金属离子13的反应。利用紫外-可见光谱研究了这些样品的光学特性。</li>
	</ol>
</li>
</ol>3. MnOx水氧化催化剂的沉积
注: 胶体 MnOx的制备和沉积程序遵循在佩雷斯-贝尼等。198915和高岛等201216, 分别。
<ol><li>胶体 MnOx溶液的制备<ol>
<li>加入39.4 毫克的 KMnO4和一个搅拌棒到30毫升烧杯。 注: 注意: KMnO4是一种高度氧化的材料;使用塑料匙, 而不是金属的。</li>
		<li>加入10毫升水的烧杯和搅拌完全溶解所有 KMnO4。</li>
		<li>添加50毫克 Na2S2O3· 5H2o 和椭圆形搅拌杆到500毫升的圆底烧瓶。</li>
		<li>加入20毫升水的烧瓶和搅拌完全溶解所有 Na2S2O3。</li>
		<li>在剧烈搅拌下加入10毫升的 KMnO4溶液到烧瓶中。 注: KMnO4溶液应缓慢添加, 以防止聚集 MnO2的形成。</li>
		<li>加入 KMnO4溶液后, 立即将470毫升蒸馏水添加到烧瓶中。</li>
		<li>保持搅拌超过2小时, 然后立即使用的解决方案为下一个过程 (喷涂)。</li>
	</ol>
</li>
	<li>在膜样品上喷涂 MnOx胶体溶液<ol>
<li>将薄膜样品放在热板上 (大约60°c), 用硅橡胶制成的口罩来确定用于沉积的区域。 注: 对于 MnOx催化剂的沉积, 应将膜样品放置在玻璃基体上。如果膜没有从基体剥离, 把它们放到热板上, 因为它们是。在沉积过程中保持膜表面湿润。该面膜还可以作为一个重量, 以防止膜起飞, 由于高气压从喷枪。</li>
		<li>添加300毫升的胶体 MnOx溶液到一个500毫升瓶连接到一个自动喷枪 (见材料表) 上方的热板和喷雾溶液到膜上。</li>
		<li>当瓶子里的体积减少时, 把剩下的胶体溶液添加到瓶子里。</li>
		<li>将样品储存在蒸馏水中, 在黑暗的条件。MnOx沉积后, 样品被称为 POM/聚乙烯醇/PAM/铈/MnOx或 POM/聚乙烯醇/PAM/Co/MnOx。</li>
		<li>利用光电测量法对聚甲醛/聚乙烯醇/PAM/Co/MnOx的可见光辐照下的电子传递特性进行了监测。为了进行光电实验, 在2O3 (ITO) 电极上制备了透明锡掺杂的膜试样。</li>
	</ol>
</li>
</ol>

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作者没有什么可透露的。

应用海伦等的交联方法是至关重要的。14开发一种独立的膜。本研究以聚醋酸乙烯为基聚合物, 对 H312O40进行聚集体, 防止自立膜的形成。然而, 当利用 Nafion 作为基聚合物制备膜时, 与 Ce3 +和 Co2 +的反应没有进展, 虽然已经实现了自立膜的制备。在本研究中, 为了保证整个膜的电子传递, 加载量被修改为 80 wt% H3密码12O<s...

利用人工光合作用或太阳能电池开发太阳能转换系统是必要的, 以便提供可替代的能源, 以改善全球气候和能源问题1、2、 3,4。光功能材料可以大致分为两组, 基于半导体的系统和基于有机分子的系统。虽然已经开发了许多不同的系统类型, 但仍需改进, 因为半导体系统缺乏精确的电荷转移控制, 而有机分子系统在光辐照。然而, 使用无机分子作为电荷转移单元的组成部分可以改善这些各自的问题。例如, 在介孔二氧化硅表面接枝的氧化桥型金属系统可以通过光辐照诱导金属-金属电荷转移 (MMCT), 并触发光化学氧化还原反应5,6,7,8,9。
我们的小组将单一原子系统扩展到一个多核系统, 利用 polyoxometalate (POM) 作为电子受体10,11,12, 并期望使用多核系统将是有利于诱导和控制多电子转移反应, 是能量转换中的一个重要概念。在本文所描述的协议中, 我们提出了用于准备基于 POM 的 MMCT 系统的详细方法, 它在聚合物矩阵中工作, 正如我们最近报告的13。膜型结构有利于阳极和阴极反应产物的分离。采用交联法, 即使具有高聚甲醛含量, 也能够形成自立膜。光电测量证明, 适当选择供体金属是触发目标的关键。POM/供体金属系统作为一种光敏剂在可见光照射下活化多电子转移催化剂。虽然这项工作利用 MnOx作为一个多电子转移催化剂的水氧化反应, 这一光功能系统也适用于其他类型的反应, 利用不同的, 捐助金属和催化剂。

<table><tbody><tr><td>Poly(vinyl Alcohol) 1000, Completely Hydrolyzed</td><td>Wako</td><td>162-16325</td><td></td></tr><tr><td>Polyacrylamide, Mv 6,000,000</td><td>Polyaciences, Inc.</td><td>2806</td><td>May contain carcinogenic monomer, acrylamide.</td></tr><tr><td>12 Tungsto(VI)phosphoric Acid n-Hydrate</td><td>Wako</td><td>164-02431</td><td>Highly acidic</td></tr><tr><td>Acetone 99.5 + %(GC)</td><td>Wako</td><td>012-00343</td><td></td></tr><tr><td>25% Glutaraldehyde Solution</td><td>Wako</td><td>079-00533</td><td></td></tr><tr><td>Hydrochloric Acid 35-37%</td><td>Wako</td><td>080-01066</td><td></td></tr><tr><td>Cerium(III) Nitrate Hexahydrate 98 + %(Ti)</td><td>Wako</td><td>031-09732</td><td></td></tr><tr><td>Cobalt(II) Chloride Hexahydrate 99 + %(Ti)</td><td>Wako</td><td>036-03682</td><td></td></tr><tr><td>Pottasium Permanganate 99.3 + %(Ti)</td><td>Wako</td><td>167-04182</td><td>Highly oxydative</td></tr><tr><td>Sodium Thiosulfate Pentahydrate 99 + %(Ti)</td><td>Wako</td><td>197-03585</td><td></td></tr><tr><td>Automatic spray gun</td><td>Lumina</td><td>ST-6</td><td></td></tr></tbody></table>

preparation of polyoxometalate-based photo-responsive membranes for the photo-activation of manganese oxide catalysts

本文提出了一种用 polyoxotungstate (12O403-)、过渡金属离子 (Ce3 +或 Co2 +) 和有机聚合物制备电荷转移染色体的方法, 其目的是实现光激活。氧演化氧化锰催化剂, 是人工光合作用的重要组成部分。采用交联技术获得了高12O403含量的自立膜。采用红外光谱和显微拉曼光谱法, 对12O403-聚合物基体中的密码的加入和结构保留进行了验证, 并通过紫外-可见光谱研究了光学特性, 揭示了金属-金属电荷转移 (MMCT) 单元的成功构造。在 MnOx氧进化催化剂沉积后, 可见光照射下的光电流测量验证了顺序电荷转移、锰→ MMCT 单元→电极, 光电流强度与氧化还原反应一致。供方金属 (Ce 或 Co) 的潜力。该方法为制备具有光功能材料的催化剂和光子吸收部件的集成系统提供了一种新的策略。

通过红外光谱和显微拉曼光谱 (图 1) 证实了聚合物基体中 POM 结构的保留;观察了与 pom Keggin 结构相对应的振动峰, 发现聚合物的峰值由于与 pom 的氢键结合而转移。光谱学分析对于确定电荷转移单元的成功构造非常有用, 而且样品的表面颜色变化也证实了这一点 (图 2)。它也得到了紫外-可见光谱和光电测量 (图 3</s...

Watch this Scientific Journal Video about Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts at JoVE.com

Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts

氧化锰催化剂光活化 Polyoxometalate 基光响应膜的制备

在这里, 我们提出了一个协议, 以准备电荷转移染色体基于 polyoxometalate/聚合物复合膜。

This paper presents a method to prepare charge-transfer chromophores using polyoxotungstate (PW12O403-), transition metal ions (Ce3+ or Co2+), and organic ...

preparation-polyoxometalate-based-photo-responsive-membranes-for

Universidad San Sebastian

Research

JoVE Journal

Chemistry

7.6K 次观看.  The University of Tokyo. 在这里, 我们提出了一个协议, 以准备电荷转移染色体基于 polyoxometalate/聚合物复合膜。

视频: Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts

Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

Photocatalytically active nanostructures require a large specific surface area with the presence of many catalytically active sites for the oxidation and reduction half reactions, and fast electron (hole) diffusion and charge separation. Nanowires present suitable architectures to meet these requirements. Axially segmented Ag|ZnO and radially segmented (coaxial) TiO2-Ag nanowires with a diameter of 200 nm and a length of 6-20 &#181;m were made by templated electrodeposition within the pores of polycarbonate track-etched (PCTE) or anodized aluminum oxide (AAO) membranes, respectively. In the photocatalytic experiments, the ZnO and TiO2 phases acted as photoanodes, and Ag as cathode. No external circuit is needed to connect both electrodes, which is a key advantage over conventional photo-electrochemical cells. For making segmented Ag|ZnO nanowires, the Ag salt electrolyte was replaced after formation of the Ag segment to form a ZnO segment attached to the Ag segment. For making coaxial TiO2-Ag nanowires, a TiO2 gel was first formed by the electrochemically induced sol-gel method. Drying and thermal annealing of the as-formed TiO2 gel resulted in the formation of crystalline TiO2 nanotubes. A subsequent Ag electrodeposition step inside the TiO2 nanotubes resulted in formation of coaxial TiO2-Ag nanowires. Due to the combination of an n-type semiconductor (ZnO or TiO2) and a metal (Ag) within the same nanowire, a Schottky barrier was created at the interface between the phases. To demonstrate the photocatalytic activity of these nanowires, the Ag|ZnO nanowires were used in a photocatalytic experiment in which H2 gas was detected upon UV illumination of the nanowires dispersed in a methanol/water mixture. After 17 min&#160;of illumination, approximately 0.2 vol% H2 gas was detected from a suspension of ~0.1 g of Ag|ZnO nanowires in a 50 ml 80 vol% aqueous methanol solution.

Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

Procedures are outlined to prepare segmented and coaxial nanowires via templated electrodeposition in nanopores. As examples, segmented nanowires consisting of Ag and ZnO segments, and coaxial nanowires consisting of a TiO2 shell and a Ag core were made. The nanowires were used in photocatalytic hydrogen formation experiments.

制备和使用光催化活性分段银|氧化锌和二氧化钛同轴<sub&gt; 2</sub&gt;银纳米线制成由模板电

Photocatalytically active nanostructures require a large specific surface area with the presence of many catalytically active sites for the oxidation and ...

科研

工程学

Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes

CMP as large surface area materials have attracted growing interest recently, due to their high variability in the incorporation of functional groups in combination with their outstanding thermal and chemical stability, and low densities. However, their insoluble nature causes problems in their processing since usually applied techniques such as spin coating are not available. Especially for membrane applications, where the processing of CMP as thin films is desirable, the processing problems have hindered their commercial application.
Here we describe the interfacial synthesis of CMP thin films on functionalized substrates via molecular layer-by-layer (l-b-l) synthesis. This process allows the preparation of films with desired thickness and composition and even desired composition gradients.
The use of sacrificial supports allows the preparation of freestanding membranes by dissolution of the support after the synthesis. To handle such ultra-thin freestanding membranes the protection with sacrificial coatings showed great promise, to avoid rupture of the nanomembranes. To transfer the nanomembranes to the desired substrate, the coated membranes are upfloated at the air-liquid interface and then transferred via dip coating.

In this paper we describe the interfacial synthesis of conjugated microporous polymers (CMP) on sacrificial substrates, and the dissolution of the substrate for the preparation of freestanding CMP nanomembranes. In addition, we will describe how the fragile nanomembranes can be transferred to other substrates.

层 - 层的合成和独立式共轭微孔聚合物纳米薄膜的转移

CMP as large surface area materials have attracted growing interest recently, due to their high variability in the incorporation of functional groups in ...

化学

Improved Heterojunction Quality in Cu2O-based Solar Cells Through the Optimization of Atmospheric Pressure Spatial Atomic Layer Deposited Zn1-xMgxO

Atmospheric pressure spatial atomic layer deposition (AP-SALD) was used to deposit n-type ZnO and Zn1-xMgxO thin films onto p-type thermally oxidized Cu2O substrates outside vacuum at low temperature. The performance of photovoltaic devices featuring atmospherically fabricated ZnO/Cu2O heterojunction was dependent on the conditions of AP-SALD film deposition, namely, the substrate temperature and deposition time, as well as on the Cu2O substrate exposure to oxidizing agents prior to and during the ZnO deposition. Superficial Cu2O to CuO oxidation was identified as a limiting factor to heterojunction quality due to recombination at the ZnO/Cu2O interface. Optimization of AP-SALD conditions as well as keeping Cu2O away from air and moisture in order to minimize Cu2O surface oxidation led to improved device performance. A three-fold increase in the open-circuit voltage (up to 0.65 V) and a two-fold increase in the short-circuit current density produced solar cells with a record 2.2% power conversion efficiency (PCE). This PCE is the highest reported for a Zn1-xMgxO/Cu2O heterojunction formed outside vacuum, which highlights atmospheric pressure spatial ALD as a promising technique for inexpensive and scalable fabrication of Cu2O-based photovoltaics.

Improved Heterojunction Quality in Cu2O-based Solar Cells Through the Optimization of Atmospheric Pressure Spatial Atomic Layer Deposited Zn1-xMgxO

Here we present a protocol for synthesizing Zn1-xMgxO/Cu2O heterojunctions in open-air at low temperature via atmospheric pressure spatial atomic layer deposition (AP-SALD) of Zn1-xMgxO on cuprous oxide. Such high quality conformal metal oxides can be grown on a variety of substrates including plastics by this cheap and scalable method.

在铜改善异质结质量<sub&gt; 2</sub&gt; O型的太阳能电池通过大气压力的空间原子层沉积的优化<br /&gt;锌<sub&gt; 1-X</sub&gt;镁<sub系列&gt; X</sub&gt; 0

Atmospheric pressure spatial atomic layer deposition (AP-SALD) was used to deposit n-type ZnO and Zn1-xMgxO thin films onto p-type thermally oxidized Cu2O ...

Morphology Control for Fully Printable Organic&#8211;Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting material. However, fullerene derivatives are air-sensitive; therefore, air-stable material is needed as an alternative. In the present study, we propose and describe the properties of Ti-alkoxide as an alternative electron-accepting material to fullerene derivatives to create highly air-stable BHJ solar cells. It is well-known that controlling the morphology in the photoactive layer, which is constructed with fullerene derivatives as the electron acceptor, is important for obtaining a high overall efficiency through the solvent method. The conventional solvent method is useful for high-solubility materials, such as fullerene derivatives. However, for Ti-alkoxides, the conventional solvent method is insufficient, because they only dissolve in specific solvents. Here, we demonstrate a new approach to morphology control that uses the molecular bulkiness of Ti-alkoxides without the conventional solvent method. That is, this method is one approach to obtain highly efficient, air-stable, organic-inorganic bulk-heterojunction solar cells.

A method for fully printable, fullerene-free, highly air-stable, bulk-heterojunction solar cells based on Ti alkoxides as the electron acceptor and the electron-donating polymer fabrication is described here. Moreover, a method for controlling the morphology of the photoactive layer through the molecular bulkiness of the Ti-alkoxide units is reported.

基于一个钛醇盐和半导体聚合物为全可印刷有机 - 无机批量异质结太阳能电池形貌控制

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting ...

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, allowing for the synthesis of isotactic poly(&#945;-hydroxy acids) with expected molecular weights (&#62;140 kDa) and narrow molecular weight distributions (Mw/Mn &#60; 1.1). This ring-opening polymerization is mediated by Ni and Zn complexes in the presence of an alcohol initiator and a photoredox Ir catalyst, irradiated by a blue LED (400 - 500 nm). The polymerization is performed at a low temperature (-15 &#176;C) to avoid undesired side reactions. The complete monomer consumption can be achieved within 4 - 8 hours, providing a polymer close to the expected molecular weight with narrow molecular weight distribution. The resulted number-average molecular weight shows a linear correlation with the degree of polymerization up to 1000. The homodecoupling 1H NMR study confirms that the obtained polymer is isotactic without epimerization. This polymerization reported herein offers a strategy for achieving rapid, controlled O-carboxyanhydrides polymerization to prepare stereoregular poly(&#945;-hydroxy acids) and its copolymers bearing various functional side-chain groups.

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

A protocol for the controlled photoredox ring-opening polymerization of O-carboxyanhydrides mediated by Ni/Zn complexes is presented.

镍/锌配合物介导的O-Carboxyanhydrides 的控制 Photoredox 环开聚合

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, ...

Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance

Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. However, the main issue limiting their applicability is their poor stability in humid conditions. The common methods to overcome this problem involve the formation of strong metal-linker bonds by using highly charged metals, which is limited to a number of structures, the introduction of alkylic groups to the framework by post-synthetic modification (PSM) or chemical vapour deposition (CVD) to enhance overall hydrophobicity of the framework. These last two usually provoke a drastic reduction of the porosity of the material. These strategies do not permit to exploit the properties of the MOF already available and it is imperative to find new methods to enhance the stability of MOFs in water while keeping their properties intact. Herein, we report a novel method to enhance the water stability of MOF crystals featuring Cu2(O2C)4&#160;paddle-wheel units, such as HKUST (where HKUST stands for Hong Kong University of Science &#38; Technology), with the catechols functionalized with alkyl and fluoro-alkyl chains. By taking advantage of the unsaturated metal sites and the catalytic catecholase-like activity of CuII ions, we are able to create robust hydrophobic coatings through the oxidation and subsequent polymerization of the catechol units on the surface of the crystals under anaerobic and water-free conditions without disrupting the underlying structure of the framework. This approach not only affords the material with improved water stability but also provides control over the function of the protective coating, which enables the development of functional coatings for the adsorption and separations of volatile organic compounds. We are confident that this approach could also be extended to other unstable MOFs featuring open metal sites.

Robust functional catechol coatings were produced in one step by direct reaction of the material known as HKUST with synthetic catechols under anaerobic conditions. The formation of homogeneous coatings surrounding the entire crystal is ascribed to the biomimetic catalytic activity of Cu(II) dimers on the external surface of the crystals.

金属-有机框架的表面功能化改善防潮性能

Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. ...

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and non-porous supports (polymer, ceramic, metal, carbon, and graphene). We developed a novel crystallization technique, which is termed the ENACT approach: the electrophoretic nuclei assembly for the crystallization of highly intergrown thin films (ENACT). This approach allows for a high density of heterogeneous nucleation of MOFs on a chosen substrate via the electrophoretic deposition (EPD) directly from the precursor sol. The growth of well-packed MOF nuclei leads to a highly intergrown polycrystalline MOF film. We show that this simple approach can be used for the synthesis of thin, intergrown zeolite imidazole framework (ZIF)-7 and ZIF-8 films. The resulting 500 nm-thick ZIF-8 membranes show a considerably high H2 permeance (8.3 x 10-6 mol m-2 s-1 Pa-1) and ideal gas selectivities (7.3 for H2/CO2, 15.5 for H2/N2, 16.2 for H2/CH4, and 2655 for H2/C3H8). An attractive performance for C3H6/C3H8 separation is also achieved (a C3H6 permeance of 9.9 x 10-8 mol m-2 s-1 Pa-1 and a C3H6/C3H8 ideal selectivity of 31.6 at 25 &#176;C). Overall, the ENACT process, owing to its simplicity, can be extended to synthesize intergrown thin films of a wide range of nanoporous crystalline materials.

A simple, reproducible, and versatile approach for the synthesis of intergrown, polycrystalline metal-organic framework membranes on a wide range of unmodified porous and non-porous supports is presented.

超薄高性能金属-有机骨架膜的电泳结晶

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and ...

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Developing photocatalytic H2 production devices is the one of the key steps for constructing a global H2-based renewable energy infrastructure. A number of photoactive assemblies have emerged where a photosensitizer and cobaloxime-based H2 production catalysts work in tandem to convert light energy into the H-H chemical bonds. However, the long-term instability of these assemblies and the need for hazardous proton sources have limited their usage. Here, in this work, we have integrated a stilbene-based organic dye into the periphery of a cobaloxime core via a distinct axial pyridine linkage. This strategy allowed us to develop a photosensitizer-catalyst hybrid structure with the same molecular framework. In this article, we have explained the detailed procedure of the synthesis of this hybrid molecule in addition to its comprehensive chemical characterization. The structural and optical studies have exhibited an intense electronic interaction between the cobaloxime core and the organic photosensitizer. The cobaloxime was active for H2 production even in the presence of water as the proton source. Here, we have developed a simple airtight system connected with an online H2 detector for the investigation of the photocatalytic activity by this hybrid complex. This photosensitizer-catalyst dyad present in the experimental setup continuously produced H2 once it was exposed in the natural sunlight. This photocatalytic H2 production by the hybrid complex was observed in aqueous/organic mixture media in the presence of a sacrificial electron donor under complete aerobic conditions. Thus, this photocatalysis measurement system along with the photosensitizer-catalyst dyad provide valuable insight for the development of next generation photocatalytic H2 production devices.

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

We have directly incorporated a stilbene-based organic dye into a cobaloxime core to generate a photosensitizer-catalyst dyad for photocatalytic H2 production. We have also developed a simple experimental setup for evaluating the light-driven H2 production by photocatalytic assemblies.

开发用于在水有条件条件下进行太阳能驱动 H2生产的光敏剂-钴氧混合剂

Developing photocatalytic H2 production devices is the one of the key steps for constructing a global H2-based renewable energy infrastructure. A number ...

Metal Oxide Heterojunction for Photocatalytic Activities

There is a significant global demand for improvements in synthesis techniques and their optimal characteristics, especially for industrial-scale applications. Sol-gel-based solution combustion synthesis (SG-SCS) is a simple method to produce ordered porous materials. In this regard, Pearson&#39;s hard and soft acids and bases theory assists in selecting host-dopant reactivity to form a proper heterojunction.
The formation of a heterojunction also changes the essential properties of the materials, improving photocatalysis via charge transfer or synergistic activities. A calcination temperature of 500 &#176;C is ideal for this process based on the results of the stability assessment via a differential thermogravimetry ratio analysis (DTG).
The nanoscale dimensions of the nanoparticles (NPs) and nanocomposites (NCs) generated were validated using X-ray diffraction and high-resolution transmission electron microscopy (HRTEM). Furthermore, the scanning electron microscopy micrographs and BET analyses confirmed the porosity nature of the materials. HRTEM, X-ray photoelectron spectroscopy, and energy-dispersive X-ray investigations established the materials composition. The study found that NCs degraded the acid orange 8 (AO8) color more efficiently than bare ZnO.

The development of a heterojunction boosts the photocatalytic activities of solution combustion synthesis, which is a time-/energy-efficient process. Advanced analytical characterization techniques were used in this protocol to evaluate the materials&#39; characteristics, and nanocomposites demonstrated improved acid orange-8 dye degradation.

There is a significant global demand for improvements in synthesis techniques and their optimal characteristics, especially for industrial-scale ...

持久性发光纳米颗粒的水热合成

Synthesis of Persistent Luminescent Nanoparticles for Rewritable Displays and Illumination Applications

Persistent luminescent nanoparticles (PLNPs) possess the capabilities to maintain extended longevity and robust emission even after the excitation has ceased. PLNPs have been widely used across various domains, including information displays, data encryption, biological imaging, and artistic decoration with sustained and vivid luminosity, providing boundless possibilities for a variety of innovative technology and artistic projects. This protocol focuses on an experimental procedure for the hydrothermal synthesis of PLNPs. The successful synthesis of enduring luminescent nanomaterials with Mn2+ or Cr3+ serving as a luminescent center in Zn2GeO4: Mn (ZGO: Mn) or ZnGa2O4: Cr highlights the universality of this synthetic method. On the other hand, the optical properties of ZGO: Mn can be changed by adjusting the pH of precursor solutions, demonstrating the tunability of the protocol. When charged with ultraviolet (UV) at a wavelength of 365 nm for 3 min and then stopped, PLNPs exhibit the remarkable capacity to generate afterglow efficiently and consistently, which makes them ideal for making two-dimensional rewritable displays and three-dimensional transparent, luminous artworks. This protocol outlined in this paper provides a feasible method for the synthesis of persistent luminescent nanoparticles for further illumination and imaging applications, opening up novel prospects for the fields of science and art.

作者聚焦：利用功能纳米材料推进生物成像和治疗

A protocol is presented for the synthesis of persistent luminescent nanomaterials (PLNPs) and their potential applications in rewritable displays and artistic processing utilizing the afterglow effect under ultraviolet light (365 nm) irradiation.

用于可擦写显示器和照明应用的持久性发光纳米颗粒的合成

Persistent luminescent nanoparticles (PLNPs) possess the capabilities to maintain extended longevity and robust emission even after the excitation has ...

氧化锰催化剂光活化 Polyoxometalate 基光响应膜的制备

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制备和使用光催化活性分段银|氧化锌和二氧化钛同轴