Synthesized Z-scheme photocatalyst ZnO/g-C3N4for enhanced photocatalytic reduction of CO2

ZnO/g-C(3)N(4)was prepared by carrying out a simple one-step calcination process. The ZnO/g-C(3)N(4)composite was characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), transient photocurrent responses and photo-luminescence (PL) spectroscopy. Compared with pure g-C3N4, the composite showed increased photocurrent under UV irradiation, and overall significantly improved photocatalytic performance. Photocatalytic experiments showed specifically the composite made of a ZnO-to-g-C(3)N(4)mass ratio of 3 : 1 displaying the best catalytic performance. The yields of CO and CH(4)under UV irradiation were, respectively, 13.4 times and 49.7 times that of g-C3N4. In addition, a direct Z-scheme electron transfer mechanism was proposed to possibly play a large role in reducing charge recombination and to effectively improve photocatalytic CO(2)reduction.