Facile synthesis of MoS2/Cu as trifunctional catalyst for electrochemical overall water splitting and photocatalytic CO2 conversion

Water splitting and CO 2 conversion are emerging energy transfer techniques to generate hydrogen and low carbon fuel as eco-friendly energy sources. Herein, a frugal and facile approach is reported for decorating MoS 2 nanosheets on copper nanorods to design MoS 2 /Cu architecture as a trifunctional catalyst for electrochemical water splitting and photocatalytic CO 2 conversion. Under optimized conditions, MoS 2 /Cu electrocatalyst shows high performance at an overpotential of 252 mV for oxygen evolution reaction and 160 mV for hydrogen evolution reaction to attain 20 mAcm −2 and 10 mAcm −2 current densities in alkaline medium. The improved efficiency is mainly credited to the synergistic effect of MoS 2 nanosheets and Cu nanorods architecture. The electrode delivered a cell voltage of ~1.508 V to impart about 10 mAcm −2 current density with high durability. Also, the negligible overpotential decay after running the cell for 12 h with 3000/HER and 2000/OER CV cycles suggests remarkable stability that makes it a promising electrocatalyst for energy production. The photocatalytic CO 2 conversion activity was also measured, where MoS 2 /Cu exhibited a significant efficiency of CO 2 to methane conversion (CH 4  ~ 23 µmol g −1 h −1 ). Based on the obtained results, it is foreseeable that this work validates the significance of transition metals tuning for electrocatalysts and photocatalysts toward more efficient water electrolysis and CO 2 reduction for potential large-scale energy applications.