MWCNT supported CuS/ZrS3 composite: A versatile multifunctional catalyst for Dye-sensitized solar cells, water splitting, and supercapacitors

Abstract

This study focuses on developing cost-effective energy conversion and storage catalysts critical for a fossil-fuel-free society. The effect of MWCNT-supported CuS/ZrS3 on the catalytic performance for dye-sensitized solar cells (DSSCs), overall water splitting, and supercapacitors had been investigated in comparison with the bare CuS/ZrS3, CuS, and ZrS3. The structure, porosity, morphology, and valence states of the composites are analyzed. Optimally, DSSCs with CuS/ZrS3/MWCNT as the counter electrode achieve 5.15 % efficiency, surpassing pristine CuS/ZrS3 at 4.21 %. The catalyst's energy storage properties reveal exceptional capacitive performance of 1214 F g−1 @ 2 A g−1 and an asymmetric supercapacitor (CuS/ZrS3/MWCNT//MWCNT) exhibiting 91 % capacitance retention after 2100 cycles, yielding an outstanding energy density of 85.1 Wh kg−1 at 3840 W kg−1 power density. The optimized CuS/ZrS3/MWCNT composite demonstrates superior bifunctional activity for hydrogen and oxygen evolution with an overpotential of 358 mV and 301 mV, respectively, at 10 mA cm−2. This enhanced performance is attributed to the combined effects of metal sulfides and MWCNT, like rich active sites, large surface area for enhanced diffusion, high conductivity, and catalytic ability. These findings propose CuS/ZrS3/MWCNT as an efficient tetrafunctional catalyst with multiple applications for future energy devices.