提高光催化剂光解水制氢效率的方法概述

光解水制氢有望解决能源危机与环境问题,成为开发新能源的研究热点之一。目前将光催化制氢技术实用化仍然面临许多难题,其中最主要问题是光解水制氢效率很低,达不到工业化生产的要求。因此,提高光解水制氢效率很有必要。本文简单概述了提高光催化剂光解水制氢效率的方法。     

可见光催化分解水制氢的研究进展

阐述了近五年来可见光催化分解水制氢的国内外最新研究进展。重点介绍了离子掺杂型光催化剂、价带控制型光催化剂、固溶体催化剂、Z型体系光催化剂、复合型光催化剂以及一些新型可见光催化剂。对今后可见光催化分解水制氢的研究工作进行了展望。     

光催化水制氢

通过表面改性的方法,以聚偏氟乙烯(PVDF)电纺纤维为基材,制备氟碳聚合物电纺纤维毡(表面含有羧基基团);在水热条件下,用含有羧基基团的氟碳聚合物电纺纤维毡作为载体,通过羧基基团对金属离子的吸附络合作用,控制半导体粒子在纤维表面的增长和成核,制备2种半导体复合光催化材料;在光化学反应仪中用制得的催化剂催化水产生氢气,初见成效。     

CDots-(001)TiO2纳米片的制备及其光解水制氢性能

以钛酸四丁酯、氢氟酸和石墨棒为原料,采用简单的水热法将具有高催化活性的碳点负载在TiO_2纳米片的(001)晶面上,制得CDots-(001)TiO_2纳米片。通过TiO_2纳米片高催化活性的(001)晶面与碳点的协同作用,提高TiO 2纳米片的光吸收、载流子的传输和分离效率,从而有效提高材料的光催化产氢性能。紫外-可见漫反射吸收谱(UV-visDRS)、光致发光光谱(PL)、瞬态光响应分析结果表明,暴露(001)晶面的TiO_2纳米片负载碳点后,可见光吸收增强,光生载流子的分离和传输速率加快,在间歇模拟太阳光照射下,CDots-(001)TiO 2纳米片的光电流密度约为TiO 2的4倍,当碳点的负载量为2%时,CDots-(001)TiO 2纳米片的光催化产氢速率达5859μmol/(h·g),量子效率达9.6%。     

Effect of Zr Substitution for Ti in KLaTiO4 for Photocatalytic Water Splitting

The effect of substitution of Zr for Ti in KLaTiO₄ with a layered perovskite structure has been studied on the photocatalytic decomposition of water under the UV light irradiation. Both the optical property and the crystallinity of KLaTiO₄ were varied by the substitution of Zr for Ti. As Zr content was increased, the crystallinity of KLaZr_xTi_1-xO₄ was increased, which had a positive effect on the photocatalytic activity in the water splitting reaction. However, the direct band gap property was lost gradually with increase of Zr content, which resulted in lowering the photocatalytic activity. As a result, the highest activity was obtained for KLaZr_0.3Ti_0.7O₄. Although the absorption coefficients of photons for KLaZr_0.1Ti_0.9O₄ and KLaTiO₄ were higher than those for KLaZr_0.3Ti_0.7O₄, the crystal structure was disordered, which resulted in lowering the activity. The nickel-loaded catalysts showed a higher activity than unloaded perovskites by a factor of greater than 2.     

半导体SiC光催化分解水制氢研究进展

简单介绍了半导体光催化分解水制氢的原理,综述了改变Si C的尺寸形貌、负载石墨烯、负载贵金属、半导体复合等方法对Si C的光催化产氢性能的影响,重点讨论了复合半导体的光催化产氢机理及SiC与其他半导体复合的研究进展,并提出前景展望。     

Nanosized Au Particles as an Efficient Cocatalyst for Photocatalytic Overall Water Splitting

The effect of the photodeposition of gold particles onto several photocatalysts on the photocatalytic activities was studied. The photocatalytic activities of K₄Nb₆O₁₇, Sr₂Nb₂O₇, KTaO₃ NaTaO₃, and NaTaO₃ doped with La for water splitting were improved when gold particles were deposited. The latter were nanoparticles, consistent with their surface plasmon absorption. The nanosized gold particle functioned as an efficient cocatalyst for photocatalytic water splitting by assisting H₂ evolution.     

用于光催化分解水制氢的含钛氧化物催化剂

综述了用于光催化分解水制氢的各种含钛氧化物催化剂的研究进展情况;重点介绍了TiO2、简单的钙钛矿型复合氧化物、层状钛酸盐和隧道结构钛酸盐的结构特征、制备方法、作用机理和光催化性能;对今后的研究方向进行了展望。     

三维WO3/rGO复合物的制备及光解水制氢性能研究

通过水热法制备出WO₃/rGO复合物用于可见光下光解水制氢。采用XRD和SEM表征手段对复合物组成、形貌进行研究,同时进行光解水制氢性能测试并对其机理进行探讨。研究结果表明,WO₃样品呈海草状,具有丰富的空隙,可以更大程度上提升光解水制氢性能,WO₃/rGO复合物与未复合石墨烯的WO₃样品比较,其形貌没有明显变化。并且还原氧化石墨烯(rGO)的导电性在提高光感应电荷载流子分离效率中也起着关键作用。WO₃/rGO复合物产氢速率为236μmol/h,而WO₃样品的产氢速率为212μmol/h,氧化石墨与WO₃复合后样品对光解水制氢性能得到提升。增强的光解水制氢性能归因于rGO的优异电导率和WO₃/rGO复合物纳米结构的协同作用。     

Visible-light-responding Bi0.5Dy0.5VO4 Solid Solution for Photocatalytic Water Splitting

Bi_0.5Dy_0.5VO₄ (BDV) oxide solid solution was synthesized by a solid state reaction method and was characterized by XRD, UV–visible DRS, BET, SEM and TEM. It has an appropriate band gap energy of ca. 2.76 eV to absorb visible light, corresponding to an absorption edge of 450 nm. When Pt-Cr₂O₃ was co-loaded, BDV could split water under UV light and visible light. The amounts of the produced hydrogen and oxygen were about 7.27 and 3.82 μmol respectively under the irradiation of visible light (λ > 420 nm) for 2 h. This study indicated that the suitable band gap of BDV for overall water splitting might be attributed to the formation of new VB due to Bi6s participating in the electronic structure.     

金属有机配合物在光解水制氢体系中的应用

实现可见光光解水制氢一直被认为是最终解决能源和环境问题的最佳途径,有效地实现可见光光解水制氢技术的关键在于光敏剂材料的制备及其改性。综述了贵金属钌Ru(Ⅱ)、铂Pt(Ⅱ)、铱Ir(Ⅲ)和铼Re(Ⅰ)的配合物、金属卟啉配合物作为光敏剂在光解水制氢体系中的应用。最后,对金属有机配合物光敏剂未来的发展趋势进行了展望。     

Photocatalytic Production of Hydrogen Peroxide over Modified Semiconductor Materials: A Minireview

Topics in Catalysis - Hydrogen peroxide (H2O2) has exhibited huge application value in many fields including chemical synthesis, medicine, environmental remediation, and fuel cells. Traditional...     

占顿染料敏化光催化制氢的影响因素探讨

分别测试了pH、载Pt、占顿染料上溴的个数等不同条件下的染料敏化光催化制氢行为。结果发现:pH为中性、载Pt的TiO_2的催化下制氢性能较好;占顿染料上溴的个数越多,制氢性能越高,特别是在载Pt的条件下,四溴荧光素(曙红Y)染料敏化的氢气产生量在2 h内可达75.2μmol,但由于脱溴导致稳定性偏差。     

The Synergistic Effects of Two Co-catalysts on Zn2GeO4 on Photocatalytic Water Splitting

Zinc orthogermanate was prepared via a hydrothermal method and a remarkable synergistic effect on the photocatalytic activity for overall water splitting was found for Zn₂GeO₄ co-loaded with noble metals (Pt, Rh, Pd, Au) and metal oxides (RuO₂, IrO₂). The photocatalytic activity of Pt-RuO₂/Zn₂GeO₄ for overall water splitting is 2.2 times of Pt/Zn₂GeO₄ and 3.3 times of RuO₂/Zn₂GeO₄. Photocatalytic half reactions evaluation of water splitting for H₂ and O₂ productions shows that Pt plays the major roles in H₂ production and RuO₂ promotes the O₂ production. The roles and valence states of co-catalysts and the mechanism of photocatalytic reaction are discussed.     

光催化“全”分解水制H_2与牺牲体系产H_2的关系

多相光催化"全"分解水制H_2的研究已走过约40年路程,至今未获得真正的突破,目前国内、外发表的许多可见光催化牺牲体系放H_2的文章,虽然它在氢离子还原机理方面有一定的参考意义,但它不能解决光催化"全"分解水制H_2问题,本文提醒我国光催化界:勿把可见光牺牲体系产H_2研究的结果,当成我们在分解水制H,方面取得的进展,应认真总结过去失败的经验教训,兼顾热力学和动力学两方面的要求,制订出正确的"全"分解水制H_2催化剂的研究策略。     

Photocatalytic Splitting of Water Over a Novel Visible-Light-Response Photocatalyst Nd2InTaO7

A new visible-light-response photocatalyst Nd₂InTaO₇ with pyrochlore-type structure crystallized in a cubic system with the space group Fd3m was synthesized by a solid-state reaction method. The H₂ evolution was obtained from Pt/CH₃OH/H₂O solution and pure H₂O, and O₂ evolution was generated from an aqueous AgNO₃ solution under visible light irradiation (λ > 400 nm). The high photocatalytic performance of Nd₂InTaO₇ supported the existing view that the photocatalytic activity correlated with the lattice distortion.