Microwave-induced growth of {101̅0} faceted zinc oxide/graphene 2D/2D nanostructures for visible-light photocatalysis and hydrogen evolution reaction

• Published in: Journal of alloys and compounds 2023-05, Vol.942, p.169071, Article 169071
• Main Authors: Louis, Jesna, Padmanabhan, Nisha Thekkekudathingal, Jayaraj, Madambi Kunjukuttan, John, Honey
• Format: Article
• Language: English
• Subjects: Bandgap tuning; Hydrogen evolution; Photocatalysis; ZnO/rGO hybrids
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.169071

The future hydrogen economy urges to replace platinum-based catalysts since large-scale production of hydrogen using platinum is not economically viable to deal with the influx of interest. Developing cost-effective, durable, and efficient catalysts is one of the most relevant research frontiers. Herein, interconnected and {101̅0} faceted 2D zinc oxide decorated on graphene sheets was effectively fabricated by a simple CTAB-assisted microwave technique and has been intensively investigated for photocatalytic dye degradation and electrocatalytic hydrogen evolution. The XRD and Raman spectra confirm the in-situ reduction of GO to rGO and successful synthesis of ZnO/rGO hybrids. Compared with the pure ZnO, as-obtained ZnO/rGO hybrids exhibited good stability and superior photocatalytic efficiency under visible-light irradiation, owing to reduced electron-hole pair recombination upon GO incorporation, as affirmed by PL spectra, TRPL lifetime measurements, and photocurrent responses. The 2D/2D ZnO/rGO hybrid nanostructure showed optimised material properties for exceptional electrochemical H2 evolution, producing a current density of − 10 mA/cm2 at a significantly reduced overpotential of − 810 mV vs. RHE, and a Tafel slope of 157 mV/dec in 0.5 M H2SO4. The enhanced catalytic activity can be attributed to the introduction of rGO sheets, which improved the surface area and electrical conductivity of the sample. The multifunctional nature of ZnO/rGO hybrids in both photocatalysis and electrocatalysis sheds light upon environmental pollution and the energy crisis. [Display omitted] •{101̅0} faceted ZnO/graphene 2D/2D nanostructures are prepared by simple one step microwave method in a short time.•Interconnected ZnO are immobilized uniformly on the surface of rGO nanosheets.•An extended visible light absorption and enhanced charge carrier separation is achieved by ZnO/rGO hybrid.•ZnO with 0.5 wt% of GO shows excellent visible light photocatalytic activity.•ZG0.5 also exhibits good electrocatalytic HER performance.