Ternary compound heterojunction from isomerism h-CdS/c-CdSe exhibits boosting photoelectrochemical and hydrogen evolution reaction properties

A novel h-CdS/c-CdSe ternary compound heterojunction catalyst CdSS is constructed from isomerism hexagonal CdS and cubic CdSe. The isomerism hexagonal CdS and cubic CdSe is the key factor to obtain the CdSS heterojunction, as compared, ternary compound CdSSe can only be prepared from isomorphic hexagonal CdS and hexagonal CdSe. Under different S:Se ratio, the main XRD peaks of CdSS displayed continuous shift between related CdS and CdSe peaks that confirms the S and Se atoms embedding CdSe and CdS lattice respectively to form atomic level ternary compound heterojunction. The photoelectrochemical and electrocatalytic results show that the CdSS catalysts have boosting properties. Under an optimal S:Se ratio, the photocurrent density of the CdSS reach 8.23 mu A/cm2, which was 4.5 times that of original CdS (1.83 mu A/cm2), 4.9 times of CdSe (1.67 mu A/cm2) and 5.1 times of CdSSe (1.60 mu A/cm2). The hydrogen evolution reaction Tafel slope of CdSS also declined 60% compared with CdS and 64% compared with CdSe. The electrocatalytic impedance and fluorescence spectra fully show that CdSS has lower internal resistance and low electron -hole recombination efficiency due to the atomic level heterojunction. The work develops a new strategy to construct high efficiency atomic level ternary compound heterojunction between isomerism homologous element compounds. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A novel h-CdS/c-CdSe ternary compound heterojunction catalyst CdSS was constructed from isomeric hexagonal CdS and cubic CdSe. Under different S:Se ratio, CdSS displayed continuous shift between related CdS and CdSe peaks, confirming the formation of atomic level ternary compound heterojunction. The CdSS catalysts showed boosted photocurrent density and decreased Tafel slope compared to CdS and CdSe. The work develops a new strategy to construct high efficiency atomic level ternary compound heterojunction between isomerism homologous element compounds.