Search

Herein, we encapsulated modified silicon carbide nanoparticles utilizing a metal–organic backbone. E-SiC-FeZnZIF composites were successfully prepared via Fe doping. The catalysis activity of this bifunctional composite material was evaluated by the degradation of tetracycline (THC) and carbamazepine (CBZ) and the reduction of carbon dioxide (CO2). Nano SiC has received widespread attention in advanced oxidation applications, especially in the catalytic activation of peroxymonosulfate (PMS). However, the inferior activity of SiC has severely restricted its practical use. In this study of dual functional composite materials, nano SiC was firstly etched under aqueous alkali. Then, zeolite imidazolate frame-8 (ZIF-8) was used for immobilization. The filling of the etched nano SiC with FeZnZiF was confirmed by SEM, XRD, FTIR, BET, and XPS analyses. In addition, E-SiC-FeZnZIF exhibited excellent catalytic activation of peroxymonosulfate (PMS) to oxidize water pollutants, which can degrade tetracycline hydrochloride (THC), achieving a removal rate of 72% within 60 min. Moreover, E-SiC-FeZnZIF exhibited a relatively high CO2 reduction rate with H2O. The yields of CO and CH4 were 0.085 and 0.509 μmol g−1, respectively, after 2 h, which are higher than that of 50 nm of commercial SiC (CO: 0.084 μmol g−1; CH4: 0.209 μmol g−1). This work provides a relatively convenient synthesis path for constructing metal skeleton composites for advanced oxidation and photocatalytic applications. This will have practical significance in protecting water bodies and reducing CO2, which are vital not only for maintaining the natural ecological balance and negative feedback regulation, but also for creating a new application carrier based on nano silicon carbide. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Photocatalytic CO 2 reduction in OFMR with transparent glass balls is studied. • For single circle and layer model, CH 3 OH concentration increases with ball number. • The closer the distance to fiber and inlet is, the higher the CH 3 OH production is. • CH 3 OH concentration rises with increasing the circle and layer numbers. • 3-circle and 5-layer balls configuration is recommended in the design of OFMR. Abstract Photocatalytic reduction of carbon dioxide to produce methanol is a promising approach to restrain greenhouse gases emissions and mitigate energy shortage, which attracts extensive concerns in recent years. The optical fiber monolith reactor with solid glass balls for photocatalytic carbon dioxide reduction is proposed in this work to increase the product concentration, and the glass balls are transparent and coated with photocatalysts evenly to absorb light. The photocatalytic reduction of carbon dioxide in optical fiber monolith reactor is numerically investigated, by which the effects of glass ball number, location, circle and layer on the production are analyzed. The results show that in the single-circle and single-layer model, the outlet methanol concentration increases with increasing the ball number. The closer to the fiber and reactor inlet the balls keep, the higher the methanol production is. As the circle and layer numbers increase, the methanol concentration also increases. The outlet methanol average concentration of the optical fiber monolith reactor with 3-circle and 5-layer balls gets 11.43% higher than the case without glass balls. [ABSTRACT FROM AUTHOR]

The production of valued added fuels and chemicals via photocatalytic carbon dioxide reduction has attracted increasing attentions in recent years. Based on the traditional twin reactor configuration, a novel bubbling twin reactor is proposed to improve the conversion of carbon dioxide to methanol in this work. The multiphysical model for the bubbling twin reactor is developed and numerically simulated. The variations of the methanol production with the gas inlet flow velocity and gas inlet number are obtained. The results show that the bubbling twin reactor has a higher carbon dioxide conversion efficiency than the traditional one. Moreover, the methanol production subsequently increases as the gas inlet velocity increases. With the constant inlet gas volumetric flow rate, the production of methanol can be improved by increasing the gas inlet number. [ABSTRACT FROM AUTHOR]