Shipeng Wan

Highly efficient simulated solar-light photocatalytic oxidation of gaseous NO with porous carbon nitride from copolymerization with thymine and mechanistic analysis

We synthesized novel and efficient porous carbon nitride (CN) photocatalysts by facial supramolecular approach using cyanuric acid (C), melamine (M) and thymine (T) as starting material. The T-modified CNs display excellent photophysical and photochemical properties: high specific surface area, strong light adsorption as well as low recombination rate of photoinduced electron–hole pairs. They exhibit tremendous enhanced photocatalytic activity on photocatalytic oxidation (PCO) of NO (∼400 ppm) under simulated solar-light irradiation, wherein the CM + 2.5 mol%-T possesses the highest photoactivity (93.3% in 40 min). The enhanced photocatalytic performance is ascribed to the synergic effect of large specific surface area and high separation and transfer efficiency of photoinduced electron–hole pairs. In the PCO of NO process, the main reaction product is NO3−, which was confirmed by Ion Chromatography. In addition, the mechanism of PCO is also intuitively analyzed by trapping experiment. The results indicate that ˙O2− plays a leading role in the PCO of NO process.

Z-scheme CaIn2S4/Ag3PO4 nanocomposite with superior photocatalytic NO removal performance: fabrication, characterization and mechanistic study

The development of the economy benefits from fossil fuels, but their consumption inevitably results in environmental pollution. For example, nitric oxide (NO) removal from coal-fired flue gas is a significant aspect of atmospheric pollution control. Based on its unique advantages to resolve atmospheric pollution, photocatalytic oxidation (PCO) is regarded as an effective technique to remove NO. Herein, we have first fabricated Z-scheme CaIn2S4/Ag3PO4 nanocomposites and studied their performance in the PCO of NO (400 ppm) with the assistance of H2O2. The results indicate that the CaIn2S4/Ag3PO4 nanocomposites exhibit superior photocatalytic performance, and the PCO efficiency of NO can reach 83.61%. The excellent photocatalytic ability belongs to the low recombination rate of the photoinduced electron–hole pairs. The production and participation of more active species is another critical factor due to the injected H2O2. FTIR and ion chromatography results reveal that NO3− is the final product. Furthermore, the fluorescence spectra combined with the electron spin resonance and the trapping experiment suggest that ˙OH and ˙O2− might play a predominant role in NO removal.

In Situ Fabrication of 3D Octahedral g-C3N4/BiFeWO x Double-Heterojunction for Highly Selective CO2 Photoreduction to CO Under Visible Light

A series of g‐C3N4/BiFeWOx composites (GN‐x/BFW) with double‐heterojunction composites as photocatalysts for efficient and stable CO2 photoreduction had been rationally designed and synthesized by the facile in situ hydrothermal method. In situ growing BFW on g‐C3N4 sheets achieved that the g‐C3N4 was embedded in the inner of BFW as well as wrapped on the surfaces of BFW. The obtained heterojunction composites greatly inhibited the recommendation of photogenerated electron/hole pairs and enhanced the light respond on the visible light due to the tight chemically bonded interface interaction. Benefiting from the unique structure, the optimized GN‐5.0 %/BFW heterostructure catalyst showed a higher performance of photoreduction CO2 to CO (43 μmol h−1 g−1) than that of pure BFW (5.2 μmol h−1 g−1) and g‐C3N4 (8.9 μmol h−1 g−1) under visible light irradiation at 10 °C. Besides, the GN‐x/BFW composites exhibited outstanding recycling photostability and structural stability. A possible Z‐scheme mechanism was proposed according to the staggered band potentials between g‐C3N4 and BFW and ESR results. Similarly, this facile synthetic method could be employed to fabricate other composites to accelerate the photocatalytic performance.

Amino‐Assisted Anchoring of CsPbBr3 Perovskite Quantum Dots on Porous g‐C3N4 for Enhanced Photocatalytic CO2 Reduction

Halide perovskite quantum dots (QDs) have great potential in photocatalytic applications if their low charge transportation efficiency and chemical instability can be overcome. To circumvent these obstacles, we anchored CsPbBr3 QDs (CPB) on NHx -rich porous g-C3 N4 nanosheets (PCN) to construct the composite photocatalysts via N-Br chemical bonding. The 20 CPB-PCN (20 wt % of QDs) photocatalyst exhibits good stability and an outstanding yield of 149 μmol h-1  g-1 in acetonitrile/water for photocatalytic reduction of CO2 to CO under visible light irradiation, which is around 15 times higher than that of CsPbBr3 QDs. This study opens up new possibilities of using halide perovskite QDs for photocatalytic application.