ZIF-67 hybridization and boron doping to enhance the photo-electrocatalytic properties of g-C3N4

Abstract

Photo-electrocatalysis is a growing field, and cobalt-based metal-organic frameworks (Co-MOFs) are attracting much interest because of their porous nature, high surface area, and malleable structure. This study investigated the photo-electrocatalytic properties of g-C3N4 and boron-doped-g-C3N4 when hybridized with cobalt-based MOF (ZIF-67). In this work, we describe the preparation of novel g-C3N4/ZIF-67 and B-g-C3N4/ZIF-67 composites by poly-condensation and co-condensation methods, respectively. ZIF-67 hybridization caused a decrease in the band gap energy of g-C3N4 due to changes in the crystalline structure and size. EIS results indicated that only B-g-C3N4/ZIF-67 showed a response to light irradiation. At the same time, both B-g-C3N4/ZIF-67 and g-C3N4/ZIF-67 demonstrated sufficient light response when the potential applied was increased to -1.2 V vs. NHE in LSV analyses. CO2 reduction to ethanol was performed for 3 hours at -1 V vs. NHE under continuous light irradiation and CO2 bubbling for each catalyst. Ethanol production rates were recorded as 10.024, 12.0168, 30.7230, and 32.1096 μmol/cm2.h for g-C3N4, B-g-C3N4, g-C3N4/ZIF-67, and B-g-C3N4/ZIF-67, respectively.