MOF-Decorated Rod-Shaped BiVO4 Heterostructures: Mutual Charge Transfer System Concerning Superior Photocatalytic Efficacy for Bromoxynil Breakdown and H2 Generation Process

The high cost of noble metals and the poor performance of non-noble-metal catalysts in scaled applications continue to be obstacles to percolate photocatalysis for producing hydrogen and degrading pollutants. Recently, non-novel metal-organic frameworks (MOFs) have received substantial interest as sacrificial templates to improve photocatalytic performance. Here, MOF-decorated non-novel metal oxide heterostructure photocatalyst is described with superior catalytic and optoelectrical properties. Through a simple hydrothermal process, a series of three-dimensional microrod mediator-free Mg-MOF-74/BiVO4 heterojunction photocatalysts were successfully produced. The morphology and composition show that the composite heterojunction materials have microrods of BiVO4 (2-4 mu m) with sparsely dispersed MOF spikes. For photocatalytic H-2 evolution and bromoxynil degradation efficiency, 1/4th wt % MOF decoration on BiVO4 stands out among other combinations. The superior carrier separation and movement between the Mg-MOF-74 and BiVO4 is considered as the main root of improved photocatalytic performance, which was further confirmed by time-resolved fluorescence spectra and photoelectrochemical measurements. Based on the results of free radical scavenging activity and EPR measurements, the heterostructures comply with a standard Z-scheme charge transfer mechanism instead of a typical Type-II heterojunction. The MOF-decorated heterostructure (25-MOF/BVO) demonstrated increased photocatalytic efficacy for bromoxynil degradation having a rate constant of 3.5 x 10(-2) min(-1).