Ammonium heptamolybdate preloaded on flexible carbon-matrix film electrode for the electrochemical phosphate sensor in a river water sample

Facile synthesis of novel molybdenum disulfide decorated banana peel porous carbon electrode for hydrogen evolution reaction

Hydrogen is one of the cleanest renewable and environmentally friendly energy resource that can be generated through water splitting. However, hydrogen evolution occurs at high overpotential, and efficient hydrogen evolution catalysts are desired to replace state-of-the-art catalysts such as platinum. In the present work, a novel molybdenum disulfide decorated banana peel porous carbon (MoS₂@BPPC) catalyst has been developed using banana peel carbon and molybdenum disulfide (MoS₂) for hydrogen evolution reaction (HER). Banana peel porous carbon (BPPC) was initially synthesized from the banana peel (biowaste) by a simple carbonization method. Subsequently, 20 wt% of bare MoS₂ was distributed on the pristine BPPC matrix using the dry-impregnation method. The resulting MoS₂@BPPC composites were systematically investigated to determine the morphology and structure. Finally, using a three-electrode cell system, pristine BPPC, bare MoS₂, and MoS₂@BPPC composite were used as HER electrocatalysts. The developed MoS₂@BPPC composite showed greater HER activity and possessed excellent stability in the acid solution, including an overpotential of 150 mV at a current density of -10 mA cm^-2, and a Tafel slope of 51 mV dec^-1. This Tafel study suggests that the HER takes place by Volmer-Heyrovsky mechanism with a rate-determining Heyrovsky step. The excellent electrochemical performance of MoS₂@BPPC composite for HER can be ascribed to its unique porous nanoarchitecture. Further, due to the synergetic effect between MoS₂ and porous carbon. The HER activity using the MoS₂@BPPC electrode advises that the prepared catalyst may hold great promise for practical applications.