Abstract
The instability in aqueous solutionshas impeded the effectiveemployment of metal-organic frameworks (MOFs) for various photocatalyticapplications. Recent literatures have proven that certain supportslike graphitic carbon nitride (g-C3N4) can improvethe water stability and meet other functionalities responsible forphotocatalytic water splitting. To expound on the mechanistic detailscentral to the photoactivity of g-C3N4/MOF systems,we relate the activity of an amorphous nickel imidazole framework(aNi-MOF) with different vacancy (carbon and nitrogen) defects ofengineered g-C3N4 systems. Vacancy defects significantlyalter the electronic structure and characteristics of photoexcitedcharge carriers and thus the photocatalytic activity of semiconductorphotocatalysts. In this framework, by elucidation of both experimentaland theoretical studies, carbon-defective g-C3N4 with aNi-MOF (CvCN/aNi) proves to be a potential candidateto speed up the photocatalytic hydrogen evolution reaction. The resultsalso potentially accord to the reactive interaction between g-C3N4 and aNi-MOF that a Ni-N bond is vitalin the photoactivity with the carbon-defective CvCN/aNiphotocatalyst producing 3922.01 mu mol g(-1) for3 h, which is 3900 and 1700 times better than those of pristine aNi-MOFand g-C3N4, respectively. Our report providesinsight into correlating the reactive mechanism in a g-C3N4/MOF system and the role of defects in photocatalytichydrogen evolution reactions.