Control of crystal growth to obtain needle-shaped violet phosphorus with excellent photocatalytic degradation performance

The control of crystal growth is important but challenging for multi-disciplinary research. Violet phosphorus, the most stable phosphorus allotrope, has recently been produced as a unique semiconducting layered structure. The crystal orientation and morphology bring extra performance due to its unique structure and anisotropy. Herein, the layered violet phosphorus has been controlled to grow along the c-axis to give tunable length up to centimeters with the assistance of tin, while the reported flat bulk ones with thickness are limited to micrometers. The as-produced needle-shaped violet phosphorus has also been demonstrated to significantly enhance the photocatalytic degradation of methyl orange pollutants due to its special crystallographic orientation. About 98.6% of methyl orange pollutants with a concentration of 50 ppm were degraded within 80 min under visible light conditions by needle-shaped violet phosphorus, which is much more effective than that of amorphous red phosphorus with only 14.1% degradation.