Engineered interfaces of WSe2/rhenium doped SnSe2 heterostructures nanosheet arrays for superior hydrogen generation and flexible supercapacitor. (December 2022) - Chauhan, Payal
Abstract: Two-dimensional hybrid heterostructures offer substantial benefits in electrochemical energy storage and conversion due to their unique compositional and structural features. It is a low-cost alternative to widely used platinum-based electrocatalysts for the commercialization approach. However, making heterostructures with other semiconductor materials bound together by van der Waals or covalent interactions is practically challenging. Here we report a hybrid electrocatalyst prepared by the hydrothermal growth of WSe2 nanosheet arrays decorated by rhenium (Re)-doped tin diselenide (SnSe2 ) (WSe2 @ReSnSe2 ). The vertically aligned high-density arrays expose more active sites and promote the charge/ion transfer due to the open porous space inside the array of hybrid heterostructure composite. Moreover, the Re doping improves the electron transfer by shifting Fermi level and also provides an active site to enhance catalytic activity. As demonstrated, WSe2 @ReSnSe2 hybrid heterostructure exhibits excellent and stable catalytic activity for hydrogen evolution with the overpotential and Tafel slope of 193 mV and 66 mV/dec in acidic medium. The fabricated flexible supercapacitor based on a hybrid heterostructure catalyst achieves the specific capacitance (Csp) of 175 F/g at a current density of 1 A/g with Csp retention rate of 84.6% after the 5, 000 cycles at 10 A/g. Graphical abstract: Image 1 Highlights: A hybrid WSe2 arrays decorated by Rhenium (Re)-doped SnSe2 (WSe2 @ReSnSe2 ) prepared by hydrothermal synthesis. The open porosity area inside the hybrid heterostructures composite array exposes more active sites and facilitates charge/ion transfer. The WSe2 @ReSnSe2 hybrid heterostructures exhibits exceptional and constant catalytic activity for hydrogen evolution, with overpotentials of 193 mV and Tafel slopes of 66 V. dec −1 . The synthesized WSe2 @ReSnSe2 composite deposited on CC for a flexible symmetric supercapacitor achieves the specific capacitance (Csp) of 175 F/g at a current density of 1 A/g. The WSe2 @ReSnSe2 electrode demonstrates the retention of 97% under bending conditions which shows excellent stability.