Rational design of selenium inserted 1T/2H mixed-phase molybdenum disulfide for energy storage and pollutant degradation applications

MoS2 based materials are recognized as the promising candidate for multifunctional applications due to its unique physicochemical properties. But presence of lower number of active sites, poor electrical conductivity, and less stability of 2H and 1T MoS2 inherits its practical applications. Herein, we synthesized the Se inserted mixed-phase 2H/1T MoS2 nanosheets with abundant defects sites to achieve improved overall electrochemical activity. Moreover, the chalcogen insertion induces the recombination of photogenerated excitons and enhances the life of carriers. The bifunctional energy storage and photocatalytic pollutant degradation studies of the prepare materials are carried out. Fabricated symmetric solid-state supercapacitor showed an exceptional capacitance of 178 mF cm−2 with an excellent energy density of 8 μWh cm−2 and power density of 137 mW cm−2, with remarkable capacitance retention of 86.34% after successive 8000 charge–discharge cycles. The photocatalytic dye degradation experiments demonstrate that the prepared Se incorporated 1T/2H MoS2 is a promising candidate for dye degradation applications. Further, the DFT studies confirmed that the Se inserted MoS2 is a promising electrode material for supercapacitor applications with higher CQ due to a larger density of states near Fermi level as compared to pristine MoS2.