Influence of electrodeposited Cu2ZnSnS4 films for the reduction of 4-nitrophenol through electronic relay approach and serve as photoelectrode in PEC device

Abstract

We explore the possibility of thin film Cu2ZnSnS4 (CZTS) as an effective catalyst for the reduction of 4-nitrophenol to 4-aminophenol in presence of NaBH4 through electronic relay process with the rate constant of 0.20 min−1, also as photoelectrode material for low-cost photoelectrochemical solar cells. Cu2ZnSnS4 thin films with thickness of ∼ 2 μm have been synthesized by an electrochemical approach. The electrochemical bath contained an aqueous solution of Cu(NO3)2·3H2O, Zn(NO3)2.6H₂O, SnC2O4 and Na2S2O3 with Citric acid as a chelating ligand at an optimum pH∼3.65. The morphology, composition, and optical properties were characterized by XRD, FE-SEM, HR-TEM, UV–Vis, FT-IR, and EPR analysis. The growth kinetics of CZTS have been invested with different time intervals, also changes of band gaps of deposited material have been noticed. Cyclic voltammetry of the electrode is done to predict the co-deposited system in the quaternary semiconductor in 0.1 M KCl as supporting electrolyte. The deposited Kesterite phase of CZTS has been systematically investigated to serve as an effective counter electrode material for photoelectrochemical (PEC) energy conversion in 0.5 M polysulfide (Na2Sx) redox couple which showed an efficiency of ∼ 4.395 %. The development of a facile and green chemical route for the preparation of a well crystallized and stable CZTS photoelectrode still remains a challenge.