Chenmin Xu

Fabrication of an exfoliated graphitic carbon nitride as a highly active visible light photocatalyst

Graphitic carbon nitride (g-C3N4) nanosheets were synthesized by exfoliating bulk g-C3N4 with a thermal treatment under H2 for the first time. The g-C3N4 nanosheets exhibited a 2D structure with a thickness of 2 nm, a high surface area and a low recombination rate of photogenerated electron–hole pairs, enhancing the visible light photocatalytic activity.

Enhancement of photocatalytic decomposition of perfluorooctanoic acid on CeO2/In2O3

CeO2-doped indium oxide photocatalysts (xCeO2/In2O3) with various CeO2 doping amounts were synthesized and systematically characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis spectra, photoluminescence spectroscopy (PL) and photocurrent measurements. The as-obtained xCeO2/In2O3 photocatalysts were used in photocatalytic degradation of PFOA for the first time and much higher photocatalytic activity of xCeO2/In2O3 than CeO2 and In2O3 was obtained under UV light irradiation. The excellent photocatalytic activity of 0.86% CeO2/In2O3 could be mainly derived from effective inhibition of recombination of photo-induced electron-holes caused by the charge transfer between CeO2 and In2O3. Moreover, the 0.86% CeO2/In2O3 catalyst showed excellent photocatalytic stability in cycling runs for the photocatalytic degradation of PFOA, providing a great potential of CeO2/In2O3 catalysts for PFOA treatment.

Macroscopic urea-functionalized cadmium sulfide material with high visible-light photocatalytic activity for rewritable paper application

A macroscopic urea-functionalized CdS (CdS-U) is synthesized for the first time. The CdS-U material is formed through the interaction between NH2/NH groups on urea and COO- groups on sodium oleate-capped CdS nanoparticles (CdS-So NPs). The CdS-U material exhibites excellent visible light photocatalytic activity and plasticity and has the potential to be produced as rewritable papers. It is convenience to produce a large-scale film by CdS-U. Letters can be written on the CdS-U film and disappear through a dissolution-irradiation process, and then the CdS-U film can be recycled by drying. This novel CdS-U material might be of interest and provide a new chance to advance the application of visible light photocatalyst on rewritable papers.

Bismuth Subcarbonate with Designer Defects for Broad-Spectrum Photocatalytic Nitrogen Fixation

A facial hydrothermal method is applied to synthesize bismuth subcarbonate (Bi2O2CO3, BOC) with controllable defect density (named BOC- X) using sodium bismuthate (NaBiO3) and graphitic carbon nitride (GCN) as precursors. The defects of BOC- X may originate from the extremely slow decomposition of GCN during the hydrothermal process. The BOC- X with optimal defect density shows a photocatalytic nitrogen fixation amount of 957 μmol L-1 under simulated sunlight irradiation within 4 h, which is 9.4 times as high as that of pristine BOC. This superior photocatalytic performance of BOC- X is attributed to the surface defect sites. These defects in BOC- X contribute to a defect level in the forbidden band, which extends the light-harvest region of the photocatalyst from the ultraviolet to the visible-light region. Besides, surface defects prevent electron-hole recombination by accommodating photogenerated electrons in the defect level to promote the separation efficiency of charge carrier pairs. This work not only demonstrates a novel and scalable strategy to synthesize defective Bi2O2CO3 but also presents a new perspective for the synthesis of photocatalysts with controllable defect density.