Ag0-loaded brookite/anatase composite with enhanced photocatalytic performance towards the degradation of methyl orange

Ag0-loaded brookite/anatase composite was prepared via an alkalescent hydrothermal process. The photocatalytic performance of as-prepared catalysts was evaluated in terms of the degradation of methyl orange (MO). The physical features of the catalysts were measured with XRD, BET and HRTEM techniques. The phase content of brookite and anatase in the TiO2 can be controlled by fixing the concentration of the electrolyte in the hydrothermal system. The as-formed Ag0 clusters have an average diameter of ca. 1.5 nm and intersperse throughout the surface of both anatase nanoparticles and brookite nanorods. Ag0 has an optimal loading dosage of 2.0 mol%, with which the photocatalytic degradation of MO are 4.82 and 2.28 times of that with Ag0-free composite and P25 TiO2, respectively. The synergistic effect of hetero-junction in brookite/anatase composite and the schottky barrier at the interface of Ag0 and TiO2 significantly improved the separation of the photogenerated electrons and holes under UV irradiation and thus resulted in a much enhanced photocatalytic reactivity towards the degradation of MO.

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► Ag0-loaded brookite/anatase TiO2 with uniform Ag0 size distribution was prepared.
► 2.0% Ag0-loaded brookite/anatase TiO2 has the highest photocatalytic reactivity.
► Hetero-junction in brookite/anatase composite benefits the charge separation.
► Schottky barrier between Ag0 and TiO2 further improved the charge separation.