The reinforced photocatalytic performance of binary-phased composites Bi-Bi12O17Cl2 fabricated by a facile chemical reduction protocol

Photocatalysis has been considered as an environmentally benign and sustainable technology for contaminants remediation and energy storage and the crucial issue is to design and fabricate catalysts with high visible-light sensitivity and photocatalytic performance. In this work, a series of binary-phased semi-metallic Bi decorated Bi12O17Cl2 composites (Bi-BOC) were constructed via a facile in-situ chemical reduction protocol using the NaBH4 as a reducing agent for the first time. X-ray diffraction patterns, X-ray photoelectron spectroscopy, and UV-vis diffuse reflection spectroscopy confirmed the real coexistence of both components that were closely contacted to form heterojunction domains in composites, as indicated by HRTEM observations. Under the visible light illumination, the as-achieved composites especially Bi-BOC-0.25 with the favorable phase composition, exerted efficient catalytic performance not only for degradation of both dye Rhodamine B and antibiotic tetracycline hydrochloride, but also for selective oxidation of benzyl alcohol. The reinforced photocatalytic capacity of these modified BOC series was mainly relevant to the effective separation of charge carriers by semimetal-semiconductor heterostructures, strengthened visible-light harvesting ability caused by the localized surface plasmon resonance effect of zero-valence Bi nanoparticles on surface, and good maintenance of original hierarchical morphology. In addition, active radicals entrapping experiments were carried out to deduce a preliminary photocatalysis mechanism.