Recent developments in visible-light photocatalytic degradation of antibiotics

The development of efficient visible-light-driven photocatalysts for water splitting has drawn much attention. Herein, we demonstrated a novel H2-producing photocatalytic system that employed nitrogen doped graphene quantum dots (NGQDs)-ZnNb2O6/g-C3N4 heterostructures as the hydrogen evolving catalysts. The as-prepared NGQDs-ZnNb2O6/g-C3N4 heterostructures were favorable for light harvesting and charge separation, and showed highly efficient photocatalytic performance for water splitting into hydrogen. Results showed that both the ZnNb2O6/g-C3N4 (Zn/CN) mole ratio and the amount of NGQDs displayed important influence for H2 production. Moreover, the optimum synthesis conditions of the Zn/CN mole ratio (1/7) and the amount of NGQDs (5%) were both obtained, and the corresponding 5%NGQDs-Zn/7CN sample performed a much higher hydrogen-evolution rate of 340.9 μmol h−1 g−1. By the further studies, the enhanced photocatalytic activity could be ascribed to the crucial roles of NGQDs and heterojunction photocatalytic system, which resulted in an efficient charge separation and the largely enhanced photocatalytic activity. Meanwhile, the possible photocatalytic mechanism of NGQDs-ZnNb2O6/g-C3N4 was also proposed. We envision that this work creates new opportunities for constructing and designing efficient visible-light-driven photocatalysts for hydrogen evolution reaction.

Constructing nitrogen doped graphene quantum dots-ZnNb2O6/g-C3N4 catalysts for hydrogen production under visible light

We report the large-scale synthesis of porous graphitic carbon nitride (g-C3N4) in a direct heat treatment process by controlling the thermal condensation temperature of the low-cost urea precursor. An excellent linear relation between the yield of the urea-derived porous g-C3N4 (U-g-C3N4) and the input urea was experimentally demonstrated, and consequently, a large-scale yield >50 g in a batch was readily achieved. A series of morphology and structure characterizations revealed the actual evolutionary process of the temperature-dependent porous architecture of U-g-C3N4 and its inherent superiority. Furthermore, we demonstrated the extraordinary visible-light-driven photodegradation activity of large-scale U-g-C3N4 toward organic pollutants such as rhodamine B, safranine T, and α-naphthol. Such superior photodegradation performance and long-term photocatalytic stability, together with a scalable preparation method, may render as-fabricated U-g-C3N4 as a promising candidate for practical application in env...

Facile Large-Scale Synthesis of Urea-Derived Porous Graphitic Carbon Nitride with Extraordinary Visible-Light Spectrum Photodegradation

Photocatalytic degradation of ofloxacin by perovskite-type NaNbO3 nanorods modified g-C3N4 heterojunction under simulated solar light: Theoretical calculation, ofloxacin degradation pathways and toxicity evolution

2D graphitic-C3N4 hybridized with 1D flux-grown Na-modified K2Ti6O13 nanobelts for enhanced simulated sunlight and visible-light photocatalytic performance

The g-C3N4 (CN) sensitized and NaNbO3 (NN) substrated II-type heterojunction (g-C3N4/NaNbO3) is prepared by a solid phase calcination method with urea and NN. The layered CN is anchoring on the surface of the cubic NN. The samples are characterized by XPS, UV-vis spectroscopy, FE-SEM, XRD and FT-IR. The photodegradation mechanism of RhB solutions under visible light irradiation is investigated. Electron paramagnetic resonance (ESR) and radical scavenger experiments reveal that the main active species is O2˙− and OH˙ also plays a role in the photodegradation process. Compared with pure CN, the CN/NN hybrid materials display excellent photocatalytic activity for rhodamine b (RhB), methyl orange (MO) and tetracycline (TC) degradation under visible-light irradiation. The 8-CN/NN sample shows the highest degradation rate (1.888 h−1) and it is 2.7 times higher than that of pure CN (0.697). The photodegradation of RhB, MO and TC by all the CN/NN photocatalysts fits to pseudo first order kinetics. The photocatalysts also possess great stability. The exploration of the CN/NN photocatalyst is significant for the further practical application of photocatalysis in wastewater treatment.

Shi Weidong

Papers

Synthesis of a g-C3N4-sensitized and NaNbO3-substrated II-type heterojunction with enhanced photocatalytic degradation activity

Estimation and experiment of axial thrust in centrifugal pump based on CFD.

Electrospinning synthesis and photocatalytic property of Fe2O3/MgFe2O4 heterostructure for photocatalytic degradation of tetracycline

Unsteady flow pressure fluctuation of high-specific-speed mixed-flow pump

Experimental Study on Orbit of Shaft Centerline of Mixed-flow Pump during Starting Period