A solar-light double illumination photoelectrocatalytic cell（SLDIPEC） was fabricated for autonomous CO2 reduction and O2 evolution with the aid of photosystem II（PS-II, an efficient light-driven water-oxidized enzyme from nature） and utilized in a photoanode solution. The proposed SLPEC system was composed of Cu foam as the photoanode and p-Si nanowires（Si-NW） as the photocathode. Under solar irradiation, it exhibited a super-photoelectrocatalytic performance for CO2 conversion to methanol, with a high evolution rate（41.94 mmol/hr）, owing to fast electron transfer from PS-II to Cu foam.Electrons were subsequently trapped by Si-NW through an external circuit via bias voltage（0.5 V）, and a suitable conduction band potential of Si（-0.6 e V） allowed CO2 to be easily reduced to CH3 OH at the photocathode. The constructed Z-scheme between Cu foam and Si-NW can allow the SLDIPEC system to reduce CO2（8.03 mmol/hr） in the absence of bias voltage. This approach makes full use of the energy band mismatch of the photoanode and photocathode to design a highly efficient device for solving environmental issues and producing clean energy.
Zichao LianDonglai PanWenchao WangDieqing ZhangGuisheng LiHexing Li
With the development of the human economy and green chemistry, people pay much more attention to environmental safety. Correspondingly, mesoporous TiO_2 and its correlated photocatalysts are able to help people seek for better life. In this review, first of all, we briefly introduce the preparations and applications of mesoporous TiO_2-SiO_2 materials, which exhibit excellent performance in pollutants decomposition and H_2 evolution in photocatalysis. Then, we review the mesoporous composites of TiSiO_2 materials, which are ideal materials used in the photoreduction of air pollutants such as CO_2, NO and NO_2. It is powerfully evident from the literature surveys that these TiO_2 based mesoporous photocatalysts possess a large potential in environment and energy development.
TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrystal films by a direct annealing method.The morphology and crystal phase of the film were controlled by adjusting the ratio of NH4F and the calcination temperature.Moreover,we found that Au nanoparticles loaded on a TiO2 mesocrystal film enabled highly efficient visible light photocatalytic properties.The photocatalytic activities were studied by hydrogen generation and photoreduction of Cr(VI).This work represents a considerable advance in the development and application of the TiO2 mesocrystals.
Bismuth oxybromide（BiOBr） with a hierarchical microcube morphology was successfully synthesized via microwave-assisted ionothermal self-assembly method. The as-obtained BiOBr was composed of regular multi-layered nanosheets, which were formed by selective adsorption of ionic liquids on the Br-terminated surface, followed by the formation of hydrogen bond-co-π-π stacking.The synthesized BiOBr exhibited high activity, excellent stability, and superior mineralization ability in the photocatalytic degradation of organic dyes under visible light owing to its enhanced light absorbance and narrow bandgap. Furthermore, photo-generated electrons were determined to be the main active species by comparison with different trapping agents used in the photocatalytic reactions.
The recovery of heterogeneous catalysts can save costs and avoid secondary pollution,but its separation efficiency and recovery cost are limited by conventional separation methods such as precipitation–flocculation,centrifugation and filtration.In this paper,we found that surface-defective metal sulfides/oxides(WS2,CuS,ZnS,MoS2,CdS,TiO2,MoO2 and ZnO)commonly used in advanced oxidation processes(AOPs)could be magnetically recovered at room temperature and atmospheric pressure by mechanically mixing with Fe3O4.Zeta potential,Raman,X-ray photoelectron spectroscopy(XPS)and electro-spin resonance(ESR)spectra were measured to explore the mechanism of the magnetic separation phenomenon.The exposed active metal sites on the surface of defective metal sulfides/oxides are beneficial for the formation of chemical bonds,which are combined with electrostatic force to be responsible for the magnetic separation.Moreover,other factors affecting the magnetic separation were also investigated,such as the addition of amount of Fe3O4,different solvents and particle sizes.Finally,WS2 was chosen to be applied as a co-catalyst in Fenton reaction,which could be well separated by the magnetic Fe3O4 to achieve the recycle of catalyst in Fenton reaction.Our research provides a general strategy for the recycle of metal sulfides/oxides in the catalytic applications.
