Developing environmental purity: Fabricated direct Z-scheme charge transfer in CuMn2O4/GO heterostructure for superior photocatalytic organic pollutant degradation and electrochemical HER evolution

The research on heterostructure material gained much attention, because of their enhanced properties compared to bare semiconductor material. Herein, heterostructure of CuMn2O4/GO nanocomposite was synthesized using a simple cost-effective physical grinding process. The formation of CuMn2O4/GO nanocomposite was identified using XRD, FT-Raman, FTIR and XPS analysis. TEM and SEM analysis demonstrated that in the composite of CuMn2O4/GO, CuMn2O4 particles were embellished on the surface of GO nanosheets. The prepared nanocomposite exhibited a superior degradation efficiency of 84.46 % against Rh B which was 5 times greater than pristine CuMn2O4. It also showed 99.82 % efficiency in the degradation of MB, whereas the pristine CuMn2O4 showed only 64.2 % efficiency under visible light irradiation. This may be due to the existence of the Z-scheme heterojunction that occurs between CuMn2O4 and GO. Moreover, the CuMn2O4/GO exhibited outstanding stability up to ten cycles. In addition, CuMn2O4/GO nanocomposite demonstrated excellent electrochemical activity for the HER in an acidic medium. The electrochemical results showed low overpotential (267.6 mV), Tafel slope (122.4 mV/dec), charge transfer resistance (2.13 Ω), and long-term stability in acidic media. This nanocomposite will act as potential candidate for the electro and photocatalytic applications, which substantiate the futuristic development of the composite in the environmental protection. [Display omitted] •CuMn2O4/GO nanocomposite was prepared by physical grinding process.•CuMn2O4/GO exhibited high photocatalytic activity and electrochemical HER evolution.•Z-scheme heterojunction enables efficient charge transfer between CuMn2O4 and GO.•O2•-, h+, and e− as the major reactive species generated Z-scheme heterojunction.