Gear-shaped mesoporous NH2-MIL-53(Al)/CdS P-N heterojunctions as efficient visible-light-driven photocatalysts.

[Display omitted] • Gear-shaped NH 2 -MIL-53(Al)/CdS p-n type heterojunctions is fabricated. • The p-n heterojunctions can form built-in field, favoring spatial charge separation. • The introduction of CdS extends the photoresponse to long wavelength region. • NH 2 -MIL-53(Al)/CdS exhibits high visible-light-driven photocatalytic performance. NH 2 -MIL-53(Al)/CdS p-n heterojunctions are fabricated via facile two-step hydrothermal method. The formation of p-n heterojunctions could form built-in field, which favors spatial charge separation. The resultant NH 2 -MIL-53(Al)/CdS p-n heterojunctions with narrowed band gap extend the photoresponse, and have a high specific surface area of 417.7 m2 g−1, and a narrow pore size of 8.8 nm. Under visible light irradiation, the photocatalytic efficiency for reduction of Cr(VI) and removal of refractory pesticide trichlorophenol is up to 99.23 and 98.85 %, respectively. The photocatalytic oxygen evolution is also as high as 563.6 μmol g−1 h−1. The excellent photocatalytic activity can be ascribed to the efficient p-n heterojunctions accelerating charge transfer and favoring spatial charge separation, and the special mesoporous structure supplying adequate surface-active sites and facilitating mass transfer. This facile strategy opens up new insights for fabricating other p-n heterojunctions photocatalysts with efficient solar energy conversion. [ABSTRACT FROM AUTHOR]