Rational construction of efficient ZnS quantum dots-supported g-C3N4 with Co3O4 heterostructure composite for bifunctional electrocatalytic hydrogen evolution reaction and environmental pollutant degradation

Bifunctional heterostructure composite catalysts of ZnS quantum dots (QDs) are incorporated with Co3O4- coupled g-C3N4 (GCOZS) for enhanced electrocatalytic hydrogen evolution reaction (HER) and photo-catalytic aqueous dye degradation performance. The phase purity, chemical composition, surface/deep morphology, and specific surface area of the as-obtained catalyst materials are determined using powder XRD, FT-IR, high-resolution XPS, FESEM with EDX mapping, HRTEM and BET analyses. The as-developed GCOZS composite catalysts exhibit an effective HER performance through a less Tafel slope of 71 mV dec1 and low overpotential of - 304 mV at the current density of 10 mA/cm2. Moreover, the GCOZS composite catalysts exhibit excellent aqueous Rhodamine B (Rh B) dye degradation efficiency (similar to 93.05 %) within 180 min of light exposure. In addition, the catalytic performance of the ternary heterostructure composite is improved owing to the efficient charge transfer pathway among intimate interfacial contacts with a high specific surface area by incorporating functional ZnS QDs and Co3O4 to the g-C3N4 layer surface. As a result, providing an efficient bifunctional electro/photocatalyst system has been of great interest for realistic en-ergy conversion in environmental applications, which may offer new designing possibilities for novel catalysts utilizing carbon-based materials. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, a bifunctional heterostructure composite catalyst (GCOZS) consisting of ZnS quantum dots and Co3O4 is synthesized on nitrogen-doped graphene for improved electrocatalytic hydrogen evolution reaction and photo-catalytic dye degradation performance. The analysis results show that GCOZS exhibits excellent performance in both electrocatalysis and photocatalysis, making it a promising catalyst for environmental applications.