增强多孔纳米红磷的光氧化和光还原性能

Hierarchically Porous Nanosized Red Phosphorus with Enhanced Photo-Oxidation and Photo-Reduction Activities

通过水热法获得了多孔纳米结构的红磷,其中水热处理24 h所得的红磷(H-RP24h)具有最高的光催化活性,光氧化罗丹明B(RhB)和光还原Cr(Ⅵ)的速率常数分别是9.2×10^-2和3.4×10^-2 min^-1,是商业红磷的23和26倍。进一步研究发现水热处理减小了红磷的尺寸、增强了光响应、提高了光生电子和空穴(h^+)的分离,从而提高了它的光催化活性。通过自由基捕获实验发现在光降解反应过程中起主要作用的活性物种是h+和超氧自由基。

The as-prepared red phosphorus showed a well-defined complicated porous and nano-sized structure,and the uppermost photocatalytic activity for the hydrothermal treatment 24 h red phosphorus(H-RP24 h).The rate constants of the H-RP24 h photo-oxidation of rhodamine B(RhB) and photo-reduction of Cr(Ⅵ) were 9.2×10^-2and 3.4×10^-2 min-1,23 and 26 times superior to those of commercial red phosphorus,respectively.Further studies demonstrated that hydrothermal treatment effectively decreased the size of red phosphorus,enhanced light response,and accelerated the detachment of photogenerated electrons and holes(h^+),thus increased its photocatalytic activity.It was found that the core reactive species in the photodegradation process were h+and superoxide ion radicals.