Synthesis of 2D-CZTS nanoplate as photocathode material for efficient PEC water splitting

Abstract

Fabrication of economically feasible photocathode for hydrogen energy production through solar water splitting is a major research among the scientific community for a decade. P-type compound Cu2ZnSnS4 (CZTS) is very interesting material due to its absorption property, earth-abundant constituents and environmental friendliness that serves as a suitable candidate to act as a photocathode. In the present work, Cu2ZnSnS4 (CZTS) nanoparticles are synthesized by simple one-step chemical method and annealed at 350 °C for three different times (60 min, 90 min, and 120 min). The effect of annealing time on the structural, optical and photoelectrochemical properties are investigated. XRD pattern indicates the formation of tetragonal crystal structure and the crystallinity increases according to the annealing time. 2D nanoplate morphology is obtained for the sample that was annealed for 120 min. From the absorption spectra, it was found that the bandgap decreases with increase of annealing time. Further, the prepared nanoparticle thin films are used as a cathode for photoelectrochemical water splitting application. Among these, the nanoparticles that are annealed for 120 min showed higher photocurrent density when compared to nanoparticles annealed for 60 min and 90 min.