Yuning Huo

Ag/BiOBr Film in a Rotating-Disk Reactor Containing Long-Afterglow Phosphor for Round-the-Clock Photocatalysis.

Ag/BiOBr film coated on the glass substrate was synthesized by a solvothermal method and a subsequent photoreduction process. Such a Ag/BiOBr film was then adhered to a hollow rotating disk filled with long-afterglow phosphor inside the chamber. The Ag/BiOBr film exhibited high photocatalytic activity for organic pollutant degradation owing to the improved visible-light harvesting and the separation of photoinduced charges. The long-afterglow phosphor could absorb the excessive daylight and emit light around 488 nm, activating the Ag/BiOBr film to realize round-the-clock photocatalysis. Because the Ag nanoparticles could extend the light absorbance of the Ag/BiOBr film to wavelengths of around 500 nm via a surface plasma resonance effect, they played a key role in realizing photocatalysis induced by long-afterglow phosphor.

BiOBr visible-light photocatalytic films in a rotating disk reactor for the degradation of organics

A facile solvothermal approach assisted with a [C16mim]Br ionic liquid for the preparation of BiOBr visible-light photocatalytic films was developed. A BiOBr film with uniformly assembled nanosheets was stably grown on the pretreated soda glass substrate via the Bi–O–Si bond. A rotating disk reactor coated with the BiOBr film was designed to effectively avoid the light shielding from color solution. The BiOBr film obtained with the [C16mim]Br ionic liquid presented an improved visible-light photcatalytic degradation rate of organics in wastewater, especially at a high concentration of organic dyes with deep color. A stable combination of BiOBr films with the substrate, the enhanced light harvesting owing to multiple reflections within the network of BiOBr nanosheets, the high separation efficiency of photo-induced charge carriers, the fast adsorption rate and the efficient utilization of light in the rotating disk reactor simultaneously played important roles in the degradation process, leading to the applicable future for the practical wastewater treatment.

BiOBr/Bi2MoO6 composite in flower-like microspheres with enhanced photocatalytic activity under visible-light irradiation

BiOBr/Bi2MoO6 composites in flower-like microspheres were synthesized by a facile solvothermal method. This photocatalyst could be activated by visible light owing to the narrow energy band gaps of both Bi2MoO6 and BiOBr. The BiOBr/Bi2MoO6 composites exhibited high activity in the photocatalytic degradation of rhodamine B and other organic pollutants under visible-light irradiation owing to enhanced light harvesting via multiple reflections inside the flower-like structure and due to the reduced photoelectron–hole recombination due to the formation of BiOBr–Bi2MoO6 heterojunctions. The dominant active species during the photocatalytic oxidation of RhB were determined as photogenerated holes and ·O2− was distinguished as the sub-main active site. The RhB mineralized into CO2 through the de-ethylation route via forming five intermediates.

Photocatalytic Composite of a Floating BiOBr@Graphene Oxide@Melamine Foam for Efficient Removal of Organics

Hierarchical photocatalytic composite BiOBr@graphene oxide@melamine foam was developed by using a solvothermal process. In this composite, the graphene oxide‐wrapped melamine foam acted as the substrate for supporting the catalyst, and the BiOBr nanosheets stably combined with the graphene oxide surface in a uniform distribution. This composite could be floated on the solution surface to inhibit the light shielding effect of colorful organic pollutants. Furthermore, the graphene oxide‐wrapped melamine foam provided mass transfer channels for organics and enriched the organics in its 3D structure. BiOBr nanosheets presented efficient photodegradation of organics and solved the problem of adsorption saturation of graphene oxide@melamine foam. Graphene oxide could further improve the light utilization, inhibit the recombination of charges, and enrich the organics. In view of the synergistic effect of adsorption and photocatalysis, this catalyst system realized the efficient removal of the organic rhodamine B and presented the promoted amount of contaminant removal with increased rhodamine B concentration.