Coupling of Solar Energy and Thermal Energy for Carbon Dioxide Reduction: Status and Prospects.

Enormous efforts have been devoted to the reduction of carbon dioxide (CO2 ) by utilizing various driving forces, such as heat, electricity, and radiation. However, the efficient reduction of CO2 is still challenging because of sluggish kinetics. Recent pioneering studies from several groups, including us, have demonstrated that the coupling of solar energy and thermal energy offers a novel and promising strategy to promote the activity and/or manipulate selectivity in CO2 reduction. Herein, we clarify the definition and principles of coupling solar energy and thermal energy, and comprehensively review the status and prospects of CO2 reduction by coupling solar energy and thermal energy. Catalyst design, reactor configuration, photo-mediated activity/selectivity, and mechanism studies in photo-thermo CO2 reduction will be emphasized. The aim of this Review is to promote understanding towards CO2 activation and provide guidelines for the design of new catalysts for the efficient reduction of CO2 .

Composite material derived from ZIF-67 and biochar promotes ozonation of 4-nitrophenol.

Cobalt 2-methylimidazole (ZIF-67) have abundant nitrogen and cobalt elements, which can be used as an excellent precursor for catalyst synthesis. In this study, a new Co, N co-doped carbon-based catalyst (Co-N-BC) was synthesized from ZIF-67 and biochar, which can significantly improve the degradation of 4-nitrophenol (4-NP) in catalytic ozonation. The mineralization rate of 4-NP achieves 65.8% within 60 min. The catalyst showed high recycling stability in the four cycles of reuse experiment. Different operating parameters, such as solution pH, the concentration of O3 and 4-NP, have been studied in the Co-N-BC catalytic ozonation. O3, O2-· and ·OH are determined as the main reactive species for 4-NP degradation, and ·OH is especially responsibly for 4-NP mineralization. The existence of inorganic ions, such as Cl-, NO2-, CO32- and PO43-, all significantly inhibited the degradation of 4-NP to different extend, respectively. The effect of substituent on a series of organics with similar structure of 4-NP was also investigated in Co-N-BC catalytic ozonation. This study provides a new composite material for heterogeneous catalytic ozonation, which is very promising in 4-NP contained complex wastewater treatment.

The structure-activity relationship of aromatic compounds in advanced oxidation processes：a review.

Advanced oxidation processes (AOPs) are widely used as efficient technologies to treat highly toxic and harmful substances in wastewater. Taking the most representative aromatic compounds (monosubstituted benzenes, substituted phenols and heterocyclic compounds) as examples, this paper firstly introduces their structures and the structural descriptors studied in AOPs before, and the influence of structural differences in AOPs with different reactive oxygen species (ROS) on the degradation rate was discussed in detail. The structure-activity relationship of pollutants has been previously analyzed through quantitative structure-activity relationship (QSAR) model, in which ROS is a very important influencing factor. When electrophilic oxidative species attacks pollutants, aromatic compounds with electron donating groups are more favorable for degradation than aromatic compounds with electron donating groups. While nucleophilic oxidative species comes to the opposite conclusion. The choice of advanced oxidation processes, the synergistic effect of various active oxygen species and the used catalysts will also change the degradation mechanism. This makes the structure-dependent activity relationship uncertain, and different conclusions are obtained under the influence of various experimental factors.

Size-controlled synthesis of colloidal gold nanoparticles at room temperature under the influence of glow discharge.

Highly dispersed colloidal gold (Au) nanoparticles were synthesized at room temperature using glow discharge plasma within only 5 min. The prepared Au colloids were characterized with UV-visible absorption spectra (UV-vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) equipped with an energy dispersion X-ray spectrometer (EDX). UV-vis, XPS and EDX results confirmed that Au3+ ions in HAuCl4 solution could be effectively reduced into the metallic state at room temperature with the glow discharge plasma. TEM images showed that Au nanoparticles were highly dispersed. The size of colloidal Au nanoparticles could be easily tuned in the nanometer range by adjusting the initial concentration of HAuCl4 solution. Moreover, the as-synthesized Au colloids (dav = 3.64 nm) exhibited good catalytic activity for glucose oxidation. The nucleation and growth of colloidal Au particles under the influence of the plasma was closely related with the high-energy electrons generated by glow discharge plasma.