【作者】 李娜；

【导师】 夏立新；

【作者基本信息】 辽宁大学 ， 无机化学， 2021， 博士

【摘要】 化石燃料枯竭、全球暖化和环境污染加剧已是很严峻的社会环境问题。氢气是公认的清洁能源,易贮存且燃烧热值高,因而如何利用太阳能制氢受到广泛的关注。模拟自然界光合作用体系,组建光电化学电池（PEC）是实现太阳能转化为氢能的有效途径。在光电化学水分解过程中,水氧化半反应涉及多电子和质子的转移,是制约光电化学电池发展的主要因素。因而,制备一种高效、稳定的光阳极对实现利用太阳能分解水制氢至关重要。本文选用多种半导体材料制备光阳极,并对其进行改性研究,提高PEC水分解性能。具体工作如下:1.用简单的水热法构建TaON/BiVO₄异质结光阳极。TaON/BiVO₄异质结能够促进光生电子-空穴对的分离和电荷转移,提高光阳极的光电催化水氧化性能。在模拟太阳光照射（AM 1.5 G,100 m W/cm²）下,外加偏压1.23 V vs.RHE时,光电化学性能测试表明,2-TaON/BiVO₄光阳极的光电流密度达到2.6 m A/cm²,是未修饰的BiVO₄电极的1.75倍。为了进一步提高复合光阳极表面的水氧化动力学,用助催化剂Co-Pi对其进行修饰,其PEC性能得到了显著改善。经测试Co-Pi/TaON/BiVO₄光阳极光电流密度高达3.6 m A/cm²。2.将金纳米粒子与分子催化剂共同修饰BiVO₄半导体光阳极,构建CoF16Pc/Au/BiVO₄功能性三组分电极。由于Au纳米粒子的plasmon效应,及与分子催化剂的相互作用,三组分电极Co F16Pc/Au/BiVO₄的光电催化效果明显优于二组分电极Au/BiVO₄和Co F16Pc/BiVO₄。在模拟太阳光照射下（AM 1.5 G,100m W/cm²）,外加偏压1.23 V vs.RHE时,其光电流密度达到4.2 m A/cm²约为未修饰的BiVO₄电极的3倍。3.制备TaON光阳极,分别用TiO₂和TaCl₅对其进行修饰,提高其水氧化活性。合成铱分子催化剂[Ir（pyalc）（H₂O）₂（μ-O）]₂²⁺,并作为助催化剂修饰光阳极。光电化学性能测试结果表明,各复合光阳极的光电流密度均显著提升。经比较Ir+NH₃+TaCl₅/TaON复合光阳极的光电流密度最高,光电催化水氧化效果最好。在模拟太阳光照射下（AM 1.5 G,100 m W/cm²）,外加电压为1.23 V vs.RHE时,其光电流密度达到84μA/cm²。4.制备GaN-ZnO、TiO₂/GaN-ZnO光阳极。用光电沉积法引入助催化剂FeOOH对其进行修饰,提高其水氧化性能。在模拟太阳光照射下（AM 1.5 G,300 m W/cm²）,外加电压为1.23 V vs.RHE时,光电化学性能测试结果表明,FeOOH/TiO₂/GaN-ZnO光阳极的光电流密度可达178μA/cm²,是未修饰GaN-ZnO光阳极的25倍。更多还原

【Abstract】 The shortage of fossil fuels and global warming have become very serious social and environmental problems.Hydrogen is a kind of clean energy with high heating value.Therefore,how to use solar energy to produce hydrogen has been attracted widespread attention.Building a photoelectrochemical cell（PEC）to mimic the photosynthesis system is an effective method to realize the conversion of solar energy into hydrogen energy.In the photoelectrochemical system,the water oxidation reaction involves the transfer of multiple electrons and protons,which is the main factor restricting the development of photoelectrochemical cells.Therefore,designing and developing high-efficiency photoanode to construct photoelectrochemical cell is the key to realize solar energy to produce hydrogen.In this paper,several semiconductor materials were used to prepare photoanodes.Different strategies were explored for PEC water splitting.The specific works are as follows:1.Constructing TaON/BiVO₄heterojunction photoanode by simple hydrothermal method.TaON/BiVO₄heterojunction photoanode can promote the separation and transfer of photogenerated electron-hole pairs,and exhibit high photoelectric catalytic water oxidation activity.Under simulated solar irradiation（AM 1.5 G,100 m W/cm²）with a bias of 1.23 V vs.RHE,the electrochemical performance tests show that the photocurrent of the 2-TaON/BiVO₄electrode reaches to 2.6 m A/cm²,which is 1.75 times that of the bare BiVO₄electrode.In order to enhance the surface water oxidation kinetics of the photoanode,the Co-Pi water oxidation cocatalyst is immobilized on the photoanode and the PEC performance is further promoted.A high photocurrent density of 3.6 m A/cm²is achieved.2.Using Au nanoparticles and molecular catalyst to modify the BiVO₄photoanode.A functional three-component photoanode Co F16Pc/Au/BiVO₄was constructed.For the plasmon effect of Au nanoparticles and the interaction with molecular catalyst,the photoelectric catalytic effect of the three-component photoanode Co F16Pc/Au/BiVO₄is significantly better than that of the two-component photoanodes Au/BiVO₄and Co F16Pc/BiVO₄.Under simulated solar irradiation（AM 1.5 G,100 m W/cm²）with a bias of 1.23 V vs.RHE,the photocurrent density of the Co F16Pc/Au/BiVO₄photoanode reaches to 4.2 m A/cm²,which is 3 times that of the bare BiVO₄electrode.3.TaON photoanodes were prepared and modified with TiO₂and TaCl₅respectively.The molecular catalyst[Ir（pyalc）（H₂O）₂（μ-O）]₂²⁺was synthesized as a cocatalyst for the photocatalytic water oxidation system.when the Ir cocatalyst was immobilized on the photoanode,the electrochemical performance test results show that the photocurrent density of each composite photoanode is significantly increased.After comparison,the photocurrent density and photoelectric catalytic water oxidation effect of Ir+NH₃+TaCl₅/TaON photoanode is the best.Under simulated solar irradiation（AM 1.5G,100 m W/cm²）with a bias of 1.23 V vs.RHE,the photocurrent density reaches to 84μA/cm².4.GaN-ZnO,TiO₂/GaN-ZnO photoanodes were fabricated.The cocatalyst FeOOH was deposited on the surface of the GaN-ZnO photoanode to improve the water oxidation performance.Under simulated solar irradiation（AM 1.5 G,300 m W/cm²）,with a bias of1.23 V vs.RHE,the photocurrent density of FeOOH/TiO₂/GaN-ZnO photoanode increased to 178μA/cm²,which is 25 times that of the bare GaN-ZnO photoanode.更多还原