posted on 2018-11-19, 00:00authored byRuifang Zhang, Fang Zeng, Fei Pang, Jianping Ge
The
introduction of photonic crystals (PC) to semiconductors, which
usually appear in the form of inverse opal materials, has been proved
to be an effective way to enhance the photocatalytic activity, but
their enhancement factor is merely two- to fourfold in most previous
reports. In this work, a supported thin-film photocatalyst (CdS/SiO2-ETPTA), as a new PC-based catalyst system, is prepared for
hydrogen evolution under visible light, which presents an 6.4- to
8.8-fold activity compared to the same CdS quantum dots deposited
on a non-PC film. This substantial enhancement originates from the
high reflectivity of PCs and absorption of reflected light by CdS,
whose absorption edge exactly matches the stopband of PCs. Compared
to the traditional inverse opal photocatalysts, the PC-supported photocatalyst
possesses many advantages including simplified procedures in synthesis,
a substantial enhancement of activity, flexible modification with
mature thin-film techniques, good stability, and easy regeneration
in reaction.