Selective synthesis of ZIFs from zinc and nickel nitrate solution for photocatalytic H2O2 production

Abstract

Hydrogen peroxide (H2O2) is one of the most promising, green, and effective oxidants that can be used in different applications. In this study, zeolitic imidazolate frameworks (ZIFs), consisting of organic ligands and metal sites, were selectively prepared from zinc or nickel nitrate solutions for use in photocatalytic H2O2 production. High concentrations of zinc nitrate solution provided more metal sites to coordinate with 2-methylimidazole, producing ZIF-8 with larger particle size, whereas low zinc nitrate concentrations resulted in more interconnected N–H⋯N hydrogen bonds, forming 2D-layered ZIF-L, with smaller particle size. Various concentrations of zinc and nickel nitrate solutions produced ZIFs that exhibited ZIF-8 or ZIF-L topology, with bandgap energies of 5.45 and 4.85 eV, respectively. These samples could serve as promising photocatalyst for the successful production of H2O2 under Xenon lamp irradiation.

Keywords

• Zinc nitrate
• Nickel nitrate
• ZIF-8
• ZIF-L
• Photocatalysis
• H2O2 production