Preparation and characterization of Ag2CrO4/few layer boron nitride hybrids for visible-light-driven photocatalysis

Nanosized Ag2CrO4/few layer boron nitride composites were prepared via in situ precipitation method. The crystal structure, morphology, optical properties, and charge carrier behavior were investigated by X-ray diffraction, transmission electrical microscopy, UV-vis diffuse reflectance spectroscopy, and electrochemical impedance spectroscopy, respectively. The photocatalytic activities of the as-prepared hybrids were discussed by degradation of rhodamine B under visible-light irradiation. Experimental results showed that the average size of pure Ag2CrO4 particles was about 20 nm. Moreover, the degradation efficiency of the as-prepared hybrids was first increased and then decreased with increasing the usage amount of few layer boron nitride nanosheets. When it was 10 wt%, in 120 min, the degradation efficiency of the as-prepared hybrids had reached the maximum of 96.7%. It was much higher than 75% of pure Ag2CrO4 nanoparticles. After 3 cycles of the degradation, the efficiency of the as-prepared composites was decreased from 96.7 to 91.8%. Trapping experiment results revealed that holes played a major role during the photocatalysis process. In addition, electrochemical impedance spectroscopy results indicated that few layer boron nitride nanosheets could enhance the separation and transfer of photogenerated electrons and holes.