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.