电荷迁移方向调控的BiVO_(4)量子点/苝四羧酸Z型异质结与纳米金修饰在人工光合成H_(2)O_(2)中的协同作用  

Synergy of charge migration direction-manipulated Z-scheme heterojunction of BiVO_(4)quantum dots/perylenetetracarboxylic acid and nanosized Au modification for artificial H_(2)O_(2)photosynthesis

作　　者：梁腾 李雨彤 徐帅 姚宇欣 许荣萍 边辑 张紫晴 井立强[1] Teng Liang;Yutong Li;Shuai Xu;Yuxin Yao;Rongping Xu;Ji Bian;Ziqing Zhang;Liqiang Jing(Key Laboratory of Functional Inorganic Materials Chemistry(Ministry of Education),School of Chemistry and Materials Science,International Joint Research Center for Catalytic Technology,Heilongjiang University,Harbin 150080,Heilongjiang,China)

机构地区：[1]黑龙江大学化学化工与材料学院,功能无机材料化学教育部重点实验室,催化技术国际联合研究中心实验室,黑龙江哈尔滨150080

出　　处：《Chinese Journal of Catalysis》2024年第7期277-286,共10页催化学报（英文）

基　　金：国家自然科学基金(U2102211,22105066,22202064,U23A20576);黑龙江省自然科学优秀青年基金(YQ2022B009,YQ2023B008).

摘　　要：利用太阳能驱动的半导体光催化技术将H_(2)O和O_(2)转化为H_(2)O_(2),是传统蒽醌工艺的可持续替代方案之一.在光催化O_(2)还原生产H_(2)O_(2)的过程中,主要涉及到O_(2)的还原和H_(2)O的氧化两个半反应.然而,单一的窄带隙半导体往往难以满足整体反应的热力学电位要求.为了克服这一挑战,研究人员借鉴自然光合作用的原理,提出了构建Z型异质结体系的策略.这种体系不仅能有效促进电荷的分离,从而增强光催化效率,而且能保留光生电荷较强的氧化还原能力,这对于H_(2)O_(2)的光合成至关重要.此外,O_(2)的活化对于H_(2)O_(2)光合成同样重要.然而,目前在构建Z型异质结时,对于Z型异质结的两组分自身电荷传输方向的匹配性鲜有关注.因此,构建具有电荷定向传输的Z型异质结,并精准负载O_(2)活化位点,对于提高H_(2)O_(2)的光合成效率和稳定性具有重要意义.本文以苝-3,4,9,10-四羧酸二酐(PTCDA)为前驱体,在水解的过程中,引入预制备的钒酸铋量子点(BQD),原位构建BQD/PTA Z型异质结.然后,通过低温辅助光还原策略将纳米Au精确修饰在苝四甲酸(PTA)上,制得具有定向电荷传输的BQD/PTA-Au Z型异质结.形貌表征结果表明,PTA的形态为平均厚度为3.5 nm的不规则纳米片,其表面均匀负载了直径约为7 nm的BQD纳米颗粒,而超小的Au纳米粒子(直径约为5 nm)则负载在PTA纳米片的边缘.优化后的BQD/PTA-Au异质结光催化H_(2)O_(2)产率为218.6μmol g^(-1)h^(-1),约为PTA纳米片的6.4倍;此外,在405 nm波长下,该异质结的表观量子产率为PTA的4.8倍.在模拟太阳光条件下,BQD/PTA-Au异质结的太阳能到化学能转换效率(SCC)为0.47%;且在连续5次的循环实验中表现出良好的稳定性.光物理和光化学测试结果表明,BQD/PTA Z型异质结的构建显著促进了PTA的电荷分离,Au修饰后复合体的电荷分离进一步增强.扫描开尔文探针(SKP)测试结果表明,BQD和PTA的能Herein,perylenetetracarboxylic acid(PTA)nanosheets with anisotropic charge migration driven by the formed internal electric fields are synthesized through a facile hydrolysis-reassembly process.Strategically,a Z-scheme heterojunction with free-flowing interfacial charge transfer and spatially separated redox centers is constructed based on the distinct photogenerated electrons and holes accumulation regions of PTA nanosheets by in-situ introducing BiVO_(4)quantum dots(BQD)and nanosized Au.The optimized BQD/PTA-Au exhibits a ca.6.4-fold and 4.8-fold enhancement in H_(2)O_(2)production rate and apparent quantum yield at 405 nm compared with pristine PTA,respectively.The exceptional activities are attributed to the cascade Z-scheme charge transfer followed the matched charge migration orientation,as well as the Au active sites for accelerating 2e-oxygen reduction pathway induced by superoxide radicals,as unraveled by electron paramagnetic resonance,in-situ irradiated X-ray photoelectron spectroscopy and in-situ diffuse reflectance infrared Fourier transformation spectroscopy.This work provides a strategy to design an efficient Z-scheme system towards solar-driven H_(2)O_(2)production.

关 键 词：Z型异质结 苝四甲酸 BiVO_(4)量子点 H_(2)O_(2)光合成 氧还原 

分 类 号：TQ123.6[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]