Ti3C2Tx MXenes decorated black phosphorus nanosheets with boosted visible-light photocatalytic activity: experiment and theory studies
Metal-free black phosphorus nanosheets (BP) have emerged as a promising photocatalyst. Herein, the 2D early transition-metal carbides and nitrides (MXenes) decorated BP (Ti3C2Tx/TiO2-BP 2D-2D) nanohybrids were constructed by hydrothermal method, in which the TiO2 was produced in hydrothermal processes. The optimized Ti3C2Tx/TiO2-BP nanohybrids exhibited a higher visible-light photodegradation efficiency of rhodamine B (99.09%) and tetracycline hydrochloride (92.70%) pollutants than that of pristine BP (12.75% and 9.35%, respectively). Diversified characterization techniques and density functional theory calculations have revealed that such enhanced photocatalytic performance was due to the synergistic effect of BP and Ti3C2Tx/TiO2, which could markedly improve the stability of BP, increase visible light absorption, prolong photoexcited electron lifetime, accelerate the photoinduced electron transfer and hinder the electron-hole (e--h+) pairs recombination. Meanwhile, the mechanism analysis indicated that •O2− radicals played a leading role in the photocatalytic process. This study will motivate great interest in using 2D MXenes as co-catalysts to enhance the activity of BP for its applications.