Efficient hydrogen production from glycerol over novel NiO/TNWs/rGO photocatalysts

Abstract

The novel NiO/TNWs/rGO ternary heterojunction photocatalyst, which demonstrates excellent photocatalytic hydrogen production from glycerol, was successfully designed and synthesized for the first time using a simple hydrothermal and alkaline photodeposition method. The structures and photoelectrochemical properties of the prepared photocatalysts were analyzed through various characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDX), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). The N_0.8T₁G_0.04 sample, which was created by uniformly depositing TNWs on the partially reduced graphene oxide (rGO) surface, resulting in a high dispersion of NiO, exhibited the lowest PL intensity, a minimum bandgap energy of 1.53 eV, and the smallest EIS arc radius. This sample demonstrated the highest photocatalytic hydrogen production efficiency from glycerol, achieving 386.32 μmol g⁻¹ h⁻¹, without any change in the structure and morphology based on the XRD and SEM characterization resulting in the promising photocatalytic stability over six repeated uses. This performance is approximately 15.3 and 5.1 times greater than that of pure TNWs and rGO samples, respectively, due to the synergistic effect of the NiO/TNWs/rGO ternary heterojunction. This study explores the preparation, characterization, and application of specific NiO/TNWs/rGO photocatalysts, aiming to provide guidance and insights for the green and clean production of hydrogen resources.