Self-assembled S-scheme In_(2.77)S_(4)/K^(+)-doped g-C_(3)N_(4)photocatalyst with selective O_(2) reduction pathway for efficient H_(2)O_(2) production using water and air  

In_(2.77)S_(4)/K^(+)掺杂g-C_(3)N_(4)自组装S型异质结光催化H_(2)O和O_(2)合成H_(2)O

作　　者：Qiqi Zhang Hui Miao Jun Wang Tao Sun Enzhou Liu 张棋祺;苗慧;王俊;孙涛;刘恩周(西北大学化工学院,西安特种能源材料重点实验室,陕西西安710127;西北大学物理学院,陕西西安710127;武汉大学电气与自动化学院,湖北武汉430072)

机构地区：[1]School of Chemical Engineering/Xi’an Key Laboratory of Special Energy Materials,Northwest University,Xi’an 710127,Shaanxi,China [2]School of Physics,Northwest University,Xi’an 710127,Shaanxi,China [3]School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,Hubei,China

出　　处：《Chinese Journal of Catalysis》2024年第8期176-189,共14页催化学报（英文）

基　　金：国家自然科学基金(22378326,22078261,11974276);陕西省自然科学基础研究计划项目(2023-JC-YB-115);陕西省重点科技创新团队项目(2022TD-33);陕西省秦创原项目(QCYRCXM-2022-213).

摘　　要：The development of an efficient artificial H_(2)O_(2) photosynthesis system is a challenging work using H_(2)O and O_(2) as starting materials.Herein,3D In_(2.77)S_(4) nanoflower precursor was in-situ deposited on K^(+)-doped g-C_(3)N_(4)(KCN)nanosheets using a solvothermal method,then In_(2.77)S_(4)/KCN(IS/KCN)het-erojunction with an intimate interface was obtained after a calcination process.The investigation shows that the photocatalytic H_(2)O_(2) production rate of 50IS/KCN can reach up to 1.36 mmol g^(-1)h^(-1)without any sacrificial reagents under visible light irradiation,which is 9.2 times and 4.1 times higher than that of KCN and In_(2.77)S_(4)/respectively.The enhanced activity of the above composite can be mainly attributed to the S-scheme charge transfer route between KCN and In_(2.77)S_(4) according to density functional theory calculations,electron paramagnetic resonance and free radical capture tests,leading to an expanded light response range and rapid charge separation at their interface,as well as preserving the active electrons and holes for H_(2)O_(2) production.Besides,the unique 3D nanostructure and surface hydrophobicity of IS/KCN facilitate the diffusion and transportation of O_(2) around the active centers,the energy barriers of O_(2) protonation and H_(2)O_(2) desorption steps are ef-fectively reduced over the composite.In addition,this system also exhibits excellent light harvesting ability and stability.This work provides a potential strategy to explore a sustainable H_(2)O_(2) photo-synthesis pathway through the design of heterojunctions with intimate interfaces and desired reac-tion thermodynamics and kinetics.过氧化氢(H_(2)O_(2))是具有广泛用途的绿色化学品,也是理想的能源载体.开发绿色高效的H_(2)O_(2)合成工艺是当前的研究热点,采用光催化技术将H_(2)O和O_(2)转化为H_(2)O_(2)是一种理想的H_(2)O_(2)制备策略.目前,设计开发具有高效光能利用率、电荷分离和利用效率的催化剂是实现该技术应用的关键.石墨相氮化碳(g-C_(3)N_(4))因其能够产生1,4-内过氧化物和超氧自由基而具有优异的双电子氧还原选择性;课题组前期研究发现(Chem.Eng.J.,2024,482,148844.),氰基修饰的K^(+)插层结晶性g-C_(3)N_(4)纳米片(KCN)具有优异的体相电荷转移效率.然而,由于KCN氧化能力不足,表面电子空穴复合快,难以实现水的高效氧化,H_(2)O_(2)产率较低.通过构建S型异质结不仅能提高KCN电荷分离效率,而且能增强其氧化能力,有利于实现水氧化反应和氧还原反应的高效协同.In_(2.77)S_(4)价带空穴具有良好的氧化能力,其能带与KCN匹配可形成S型异质结,满足H_(2)O和O_(2)合成H_(2)O_(2)的热力学条件.本文采用原位溶剂热法及煅烧法制备样品.首先将KCN纳米片引入In_(2.77)S_(4)的生长体系中,成功诱导了KCN与In_(2.77)S_(4)自组装,最终形成了3D分级In_(2.77)S_(4)/KCN纳米花,二者之间形成了紧密的2D/2D异质界面.密度泛函理论计算、光电化学测试、电子顺磁共振和自由基捕获实验结果表明,In_(2.77)S_(4)和KCN之间形成了S型电荷迁移路径,在能带弯曲、内建电场和库仑引力作用下,KCN价带空穴和In_(2.77)S_(4)导带电子在界面处快速复合,使具有强氧化还原能力的In_(2.77)S_(4)价带空穴和KCN导带电子得到保留,提高了载流子分离效率及水氧化反应热力学驱动力.研究结果表明,该异质结表面具有疏水性,形成了气液固三相接触界面,同时其独特的三维分级纳米结构加快了空气中O_(2)向催化剂活性中心的扩散和吸附.氧还原反应能垒计算表明,异质结表面�

关 键 词：Photocatalysis H_(2)O_(2) production K^(+)-doped g-C_(3)N_(4) In_(2.77)S_(4) S-scheme heterojunction 

分 类 号：TQ113.26[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]