可见光下光催化分解水制氢的研究进展

利用太阳能驱动光催化反应制备氢气成为了目前的研究热点。综述了近年来在可见光下光催化分解水制氢的研究进展,着重介绍了固溶体光催化剂、非金属化合物型光催化剂、Z型光催化系统及新型助催化剂的最新研究成果,并展望了光催化制氢的发展。     

Ag-基等离子体共振光催化剂的研究进展

Ag-基等离子体共振光催化剂因其特殊的物理化学性能,在光催化降解污染物、分解水和生物传感器等方面受到了广泛关注。尤其是Ag/AgX(X=Cl、Br、I)类等离子体光催化剂,由于其在可见光催化降解有机污染物中的优异表现,成为近年来可见光催化领域的研究热点。综述了近年来Ag-基等离子体共振光催化剂的研究进展,并深入探讨了其光催化反应机理。Ag-基等离子体共振光催化剂合成方法简单易行,原料成本低,光催化效率高,必将在应用光催化领域具有良好的发展前景。     

南京大家研发成功新型太阳能电池材料和制备技术

据有关媒体报导，在利用具有可见光反应的半导体光催化剂，直接通过太阳能分解水生产氢气的研究方面，南京大学居世界领先地位。据悉，该校这方面的研究工作，是由著名的中青年专家、“长江学者”邹志刚教授领导的科研团队完成的。该校在世界上首次开发成功可见光响应型水全分解光催化剂；在世界上首次实现了在实际太阳光下光催化分解水制氢。现已开发成功具有可视光反应的半导体光催化剂，直接由太阳能分解有毒有害气体和物质，净化已被污染的环境；该校在世界上首次开发成功了室内用可见光响应型高效光催化剂；     

Rose bengal-Cu-TiO2的制备及可见光制氢活性研究

用光还原方法制备了负载Cu的光催化剂Cu-TiO2,用染料Rose bengal敏化Cu-TiO2制备了具有可见光活性的Rose bengal-Cu-TiO2光催化剂,通过可见光(λ≥420nm)下分解水制氢考察了催化剂的活性,利用XRD、UV-vis吸收光谱对样品进行了表征.结果表明:载Cu增强了TiO2对可见光的吸收,Cu负载量对催化剂活性有一定的影响,Cu的最佳负载量为5%(质量分数).Cu的负载也增加了TiO2对染料的吸附,从而提高了TiO2对可见光的吸收和光催化活性.     

新型可见光催化剂BiVO4的制备方法

作为一种新型可见光催化剂,钒酸铋（BiVO₄）因为拥有较窄的禁带宽度（2.4eV）以及合适的导带和价带位置在可见光催化领域受到广泛关注,在水的光解以及有机污染物的降解等方面都有研究及应用。不同的制备方法对材料的形貌和结构都有较大的影响,进而影响到光催化剂的光催化性能。综述了国内外BiVO₄的制备方法,并在此基础上展望了该领域的发展方向。     

TiO2光催化活性向可见光区拓展的研究进展

TiO2光催化剂可用于光分解有机污染物,组装太阳能电池,光分解水制氢气或氧气等领域。本文对可见光响应的TiO2光催化剂国内外研究进行了综述,概述了采用敏化,掺杂等方法可使二氧化钛光催化活性从紫外光区拓展到可见光区,并对未来的研究方向进行了展望。     

Zn_xTiO_yN_z的制备及其在可见光下制氢的研究

为研制具有可见光响应的光催化剂,本文以硝酸锌和钛酸四丁酯为原料,通过溶胶-凝胶法和高温气固相氮化反应制备了具有可见光响应的新型光催化剂ZnxTiOyNz.并用X射线衍射仪、X射线光电子能谱和紫外-可见漫反射光谱等测试手段对其结构进行了表征.同时还研究了Pt的负载量对光催化分解水制氢反应活性的影响.结果表明:在大于400nm的可见光照射下,在Pt的负载量为1.8wt%(质量百分比)时,产氢速率为36.2μmolh-1.     

光解水制氢半导体光催化材料的研究进展

自从Fujishima-Honda效应发现以来,科学研究者一直努力试图利用半导体光催化剂光分解水来获得既可储存而又清洁的化学能--氢能.近一二十年来,光催化材料的研究经历了从简单氧化物、复合氧化物、层状化合物到能响应可见光的光催化材料.本文重点描述了这些光催化材料的结构和光催化特性,阐述了该课题的意义和今后的研究方向.     

需要牺牲剂可见光下分解水的光催化材料

介绍了需要牺牲剂在可见光下光催化材料分解水的原理 ,以及典型的几类该种催化剂 ,并展望了其发展前景     

光解水制氢的可见光催化材料的研究进展

利用可见光催化分解水制氢是利用太阳能的有效方法之一,从材料组成、结构、催化性能及改性等方面介绍了几类重要的可见光催化材料的研究进展,并展望了未来的发展方向.     

磷烯光催化分解水研究进展

半导体光催化分解水被认为是解决全球能源短缺和环境污染问题的潜在途径之一。近年来, 磷烯(BP)由于具有带隙可调、空穴迁移率高、吸收光谱宽等特性而在光催化分解水方面得到了广泛关注。本文综述了国内外近年来在磷烯光催化分解水领域所取得的重要研究进展, 总结了磷烯基光催化剂的合成方法、表面修饰和异质结构构建等改性策略, 阐述了磷烯基光催化剂的构-效关系和电荷转移机制, 并展望了磷烯基光催化剂所面临的机遇和挑战, 揭示了磷烯基材料在太阳能利用和转化方面的重要应用潜力。     

钽酸盐光催化分解水研究进展

钽酸盐光解水催化剂,因其特殊的晶体结构和能带结构而具有高的光解水活性。结合本课题组工作,论述了钽酸盐光解水催化剂的种类、结构特点、制备方法及发展趋势,以期为今后的光解水制氢研究提供参考依据。     

Recent Advances in Conjugated Polymers for Visible-Light-Driven Water Splitting

With the ambition of solving the challenges of the shortage of fossil fuels and their associated environmental pollution, visible-light-driven splitting of water into hydrogen and oxygen using semiconductor photocatalysts has emerged as a promising technology to provide environmentally friendly energy vectors. Among the current library of developed photocatalysts, organic conjugated polymers present unique advantages of sufficient light-absorption efficiency, excellent stability, tunable electronic properties, and economic applicability. As a class of rising photocatalysts, organic conjugated polymers offer high flexibility in tuning the framework of the backbone and porosity to fulfill the requirements for photocatalytic applications. In the past decade, significant progress has been made in visible-light-driven water splitting employing organic conjugated polymers. The recent development of the structural design principles of organic conjugated polymers (including linear, crosslinked, and supramolecular self-assembled polymers) toward efficient photocatalytic hydrogen evolution, oxygen evolution, and overall water splitting is described, thus providing a comprehensive reference for the field. Finally, current challenges and perspectives are also discussed.     

Plasmon resonant enhancement of photocatalytic water splitting under visible illumination

We demonstrate plasmonic enhancement of photocatalytic water splitting under visible illumination by integrating strongly plasmonic Au nanoparticles with strongly catalytic TiO2. Under visible illumination, we observe enhancements of up to 66× in the photocatalytic splitting of water in TiO2 with the addition of Au nanoparticles. Above the plasmon resonance, under ultraviolet radiation we observe a 4-fold reduction in the photocatalytic activity. Electromagnetic simulations indicate that the improvement of photocatalytic activity in the visible range is caused by the local electric field enhancement near the TiO2 surface, rather than by the direct transfer of charge between the two materials. Here, the near-field optical enhancement increases the electron-hole pair generation rate at the surface of the TiO2, thus increasing the amount of photogenerated charge contributing to catalysis. This mechanism of enhancement is particularly effective because of the relatively short exciton diffusion length (or minority carrier diffusion length), which otherwise limits the photocatalytic performance. Our results suggest that enhancement factors many times larger than this are possible if this mechanism can be optimized.     

Unveiling the Origin of Co3O4 Quantum Dots for Photocatalytic Overall Water Splitting

Spinel cobalt oxide displays excellent photocatalytic performance, especially in solar driven water oxidation. However, the process of water reduction to hydrogen is considered as the Achilles’ heel of solar water splitting over Co₃O₄ owing to its low conduction band. Enhancement of the water splitting efficiency using Co₃O₄ requires deeper insights of the carrier dynamics during water splitting process. Herein, the carrier dynamic kinetics of colloidal Co₃O₄ quantum dots-Pt hetero-junctions is studied, which mimics the hydrogen reduction process during water splitting. It is showed that the quantum confinement effect induced by the small QD size raised the conduction band edge position of Co₃O₄ QDs, so that the ligand-to-metal charge transfer from 2p state of oxygen to 3d state of Co²⁺ occurs, which is necessary for overall water splitting and cannot be achieved in Co₃O₄ bulk crystals. The findings in this work provide insights of the photocatalytic mechanism of Co₃O₄ catalysts and benefit rational design of Co₃O₄-based photocatalytic systems.     

纳米异质结光催化材料制取太阳能燃料研究进展

光催化制取太阳能燃料主要包括光催化分解H₂O制取H₂及光催化还原CO₂制取碳氢化合物, 是应对能源危机最具前景的方法之一。目前, 太阳能燃料的最高转化效率为5%, 无法满足商业化要求(≥10%)。纳米异质结由于能展现出单组分纳米材料或体相异质结所不具备的独特性质, 更能促进光生电子和空穴快速转移, 提供更多的光生电子或使光生电子具有更强的还原性, 因而能显著提高光催化活性。本文主要综述了几种纳米异质结(I-型、II-型、p-n型及Z-型)的光催化原理及其在制取太阳能燃料方面的研究进展, 并展望了研究发展方向。     

利用太阳能制氢的方法及发展现状

发展清洁可再生能源是人类面临的巨大技术挑战,氢气作为一种理想的清洁能源,其制取及储运技术近年来都取得了很大进展。综述了利用太阳能分解水制氢的基本途径及发展现状,主要包括电解水制氢及人工模拟光合作用制氢、半导体光解水及其催化剂以及最有希望实现的高温热化学循环分解水制氢技术。     

Recent progress in oxynitride photocatalysts for visible-light-driven water splitting

Photocatalytic water splitting into hydrogen and oxygen is a method to directly convert light energy into storable chemical energy, and has received considerable attention for use in large-scale solar energy utilization. Particulate semiconductors are generally used as photocatalysts, and semiconductor properties such as bandgap, band positions, and photocarrier mobility can heavily impact photocatalytic performance. The design of active photocatalysts has been performed with the consideration of such semiconductor properties. Photocatalysts have a catalytic aspect in addition to a semiconductor one. The ability to control surface redox reactions in order to efficiently produce targeted reactants is also important for photocatalysts. Over the past few decades, various photocatalysts for water splitting have been developed, and a recent main concern has been the development of visible-light sensitive photocatalysts for water splitting. This review introduces the study of water-splitting photocatalysts, with a focus on recent progress in visible-light induced overall water splitting on oxynitride photocatalysts. Various strategies for designing efficient photocatalysts for water splitting are also discussed herein.     

Extended visible light harvesting and boosted charge carrier dynamics in heterostructured zirconate–FeS<Subscript>2</Subscript> photocatalysts for efficient solar water splitting

Limited visible light absorption, slow charge transference, and high recombination are some of the main problems associated with low efficiency in photocatalytic processes. For these reasons, in the present work, we develope novel zirconate–FeS₂ heterostructured photocatalysts with improved visible light harvesting, effective charge separation and high photocatalytic water splitting performance. Herein, alkali and alkaline earth metal zirconates are prepared by a solid state reaction and coupled to FeS₂ through a simple wet impregnation method. The incorporation of FeS₂ particles induces visible light absorption and electron injection in zirconates, while the appropriate coupling of the semiconductors in the heterostructure allows an enhanced charge separation and suppression of the recombination. The obtained heterostructures exhibit high and stable photocatalytic activity for water splitting under visible light, showing competitive efficiencies among other reported materials. The highest hydrogen evolution rate (4490 µmol g^?1 h^?1) is shown for BaZrO₃–FeS₂ and corresponds to more than 20 times the activity of the bare BaZrO₃. In summary, this work proposes novel visible light active heterostructures for efficient visible light photocatalytic water splitting.     

Carbon nitride photocatalyst with internal electric field induced photogenerated carriers spatial enrichment for enhanced photocatalytic water splitting

Photocatalytic water splitting is a cost-effective way to convert sustainable solar energy into chemical energy. Among various photocatalytic systems, coupling the H₂- and O₂- evolving photocatalysts has been widely used in photocatalytic water splitting. However, due to the close spatial distance between surface electrons and surface holes, this heterogeneous material easily catalyzes the unwanted reverse reaction, limiting the solar energy conversion efficiency. Here we present a carbon nitride nanosheet (CNN) homojunction which possesses electrons-enriched region and holes-enriched region induced by the interfacial internal electric field. The reverse reactions are significantly suppressed by benefiting from the spatial separation of the oxidation (+2.21 V) and reduction (-1.19 V) regions. The homojunction exhibits efficient photocatalytic activity for H₂ and O₂ evolution (1270.5 and 36.0 μmol h⁻¹) with the scavenger. Meanwhile, the solar-to-hydrogen efficiency of overall water splitting was improved to 0.14%. This research provides a new way for semiconductor design in solar energy conversion applications.