Qi Xie a,1, Min Wang a,1, Yong Xu a, Xiaoke Li a, Xin Zhou b,*, Liang Hong c, Luhua Jiang a,*, Wen-Feng Linc,*
a Nanomaterials and Electrocatalysis Laboratory, College of Materials and Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong, China
b College of Environment and Chemical Engineering, Dalian University, Dalian Economic Technological Development Zone, Dalian 116622, Liaoning, China
c Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
1 These authors contributed equally to this work.
* Corresponding authors.
E-mail addresses: luhuajiang@qust.edu.cn (L. Jiang), zhouxin@dlu.edu.cn (X. Zhou), w.lin@lboro.ac.uk (W.F. Lin)
Abstract
Energy band structure and interfacial compatibility of heterojunctions are crucial for photocatalysts in promoting photogenerated charge separation and transfer. Here, a combined strategy of vacancy engineering and quantum effect via a facile phosphating process is reported, for the first time, to modulate the energy band structure and the interface of ZnxCd1−xS/CoP quantum dots (ZCSv/CoP QDs) heterojunction. The combined experimental and theoretical investigation revealed that phosphating process transformed CoOx QDs to CoP QDs, and more importantly, generated considerable amount of sulfur vacancies in ZCSv. As a result, a Type II ZCSv/CoP QDs heterojunction with compatible interfaces was constructed via in-situ generated P-Zn, P-Cd and S-Co bonds, which facilitated the separation and transfer of the photogenerated charge and thus resulted in a high ability towards hydrogen evolution under visible light (17.53 mmol g−1 h−1). This work provides an effective and adaptable strategy to modulate band structure and interfacial compatibility of heterojunctions via vacancy engineering and quantum effect.
Keywords: Visible light excited photocatalyst; Heterojunction; ZnxCd1−xS/CoP quantum dot; S vacancy engineering; Photocatalytic hydrogen evolution
DOI: 10.1016/j.jechem.2021.03.019
