Type-II Heterojunction CdIn2S4/BiVO4 Coupling with CQDs to Improve PEC Water Splitting Performance Synergistically

Jiachen Wang; Tingsheng Zhou; Yan Zhang; Lei Li; Changhui Zhou; Jing Bai; Jinhua Li; Hong Zhu; Baoxue Zhou

doi:10.1021/acsami.2c12618

Type-II Heterojunction CdIn₂S₄/BiVO₄ Coupling with CQDs to Improve PEC Water Splitting Performance Synergistically

ACS Appl Mater Interfaces. 2022 Oct 12;14(40):45392-45402. doi: 10.1021/acsami.2c12618. Epub 2022 Sep 30.

Authors

Jiachen Wang¹, Tingsheng Zhou¹, Yan Zhang¹, Lei Li¹, Changhui Zhou¹, Jing Bai¹, Jinhua Li¹, Hong Zhu², Baoxue Zhou^{1

3}

Affiliations

¹ School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai200240, P. R. China.
² University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai200240, P. R. China.
³ Shanghai Institute of Pollution Control and Ecological Security, Shanghai200092, P. R. China.

PMID: 36179059
DOI: 10.1021/acsami.2c12618

Abstract

Bismuth vanadate (BiVO₄) has been considered as a promising photoelectrocatalytic (PEC) semiconductor, but suffers from severe hole recombination, attributed to the short hole-diffusion length and the low carrier mobility. Herein, a type-II heterojunction CdIn₂S₄/BiVO₄ is designed to improve the photocurrent density from 1.22 (pristine BiVO₄) to 2.68 mA cm^-2 at 1.23 V vs the reversible hydrogen electrode (RHE), accelerating the bulk separation of photogenerated carriers by the built-in field from the matched energy band. With the introduction of CQDs, CQDs/CdIn₂S₄/BiVO₄ increases the photocurrent density to 4.84 mA cm^-2, enhancing the light absorption and cathodically shifting its onset potential, due to the synergetic effect of the heterojunction and CQDs. Compared with BiVO₄, CQDs/CdIn₂S₄/BiVO₄ promotes the bulk separation efficiency to 94.6% and the surface injection efficiency to 72.2%. Additionally, spin-coating of FeOOH on CQDs/CdIn₂S₄/BiVO₄ could further improve the PEC performance and keep a long stability for water splitting. The density function theory (DFT) calculations illustrated that the type-II heterojunction CdIn₂S₄/BiVO₄ could decrease the oxygen evolution reaction (OER) overpotential and accelerate bulk charge separation for the built-in field of the aligned band structure.

Keywords: bismuth vanadate (BiVO4); cadmium indium sulfide (CdIn2S4); carbon quantum dots (CQDs); density function theory (DFT); type-II heterojunction.