Photocatalytic hydrogen evolution from water has received enormous attention due to its ability to address a number of global environmental and energy-related issues. Here, we synthesize 2D/2D Ti3C2/g-C3N4 composites by electrostatic self-assembly technique and demonstrate their use as photocatalysts for hydrogen evolution under visible light irradiation. The optimized Ti3C2/g-C3N4 composite exhibited a 10 times higher photocatalytic hydrogen evolution performance (72.3 μmol h-1 gcat-1) than that of pristine g-C3N4 (7.1 μmol h-1 gcat-1). Such enhanced photocatalytic performance was due to the formation of 2D/2D heterojunctions in the Ti3C2/g-C3N4 composites. The intimate contact between the monolayer Ti3C2 and g-C3N4 nanosheets promotes the separation of photogenerated charge carriers at the Ti3C2/g-C3N4 interface. Furthermore, the ultrahigh conductivity of Ti3C2 and the Schottky junction formed between g-C3N4/MXene interfaces facilitate the photoinduced electron transfer and suppress the recombination with photogenerated holes. This work demonstrates that the 2D/2D Ti3C2/g-C3N4 composites are promising photocatalysts thanks to the ultrathin MXenes as efficient co-catalysts for photocatalytic hydrogen production.

2D/2D heterojunction of Ti 3 C 2 /g-C 3 N 4 nanosheets for enhanced photocatalytic hydrogen evolution.

Oxygen vacancy plays an important role in many fields, such as photocatalysis, energy storages, electro-catalysis, which has been widely investigated both by experiment and theoretical calculations. Herein, this review presents the new type and advanced methods to detect the existence of oxygen vacancies in nanomaterials, such as, electron paramagnetic resonance, synchrotron radiation-based X-ray absorption fine structure, X-ray photoelectron spectroscopy and positron annihilation spectroscopy measurements. In addition, we provide some perspectives on the challenge and new direction for future research in oxygen vacancy. We hope that this minireview can offer some useful contributions to the future development of defective nanomaterials for diverse application.

An overview of advanced methods for the characterization of oxygen vacancies in materials

Integrated adsorption and photocatalytic degradation of volatile organic compounds (VOCs) using carbon-based nanocomposites: A critical review.

The availability of robust, versatile, and efficient photocatalysts is the main bottleneck in practical applications of photocatalytic degradation of organic pollutants. Herein, N‐WO3/Ce2S3 nanotube bundles (NBs) are synthesized and successfully immobilized on a carbon textile, resulting in a flexible and conducting photocatalyst. Due to the large interfacial area between N‐WO3 and Ce2S3, the interwoven 3D carbon architecture and, more importantly, the establishment of a heterojunction between N‐WO3 and Ce2S3, the resultant photocatalyst exhibits excellent light absorption capacity and superior ability to separate photoinduced electron–hole pairs for the photocatalytic degradation of organic compounds in air and water media. Theoretical calculations confirm that the strong electronic interaction between N‐WO3 and Ce2S3 can be beneficial to the enhancement of the charge carrier transfer dynamics of the as‐prepared photocatalyst. This work provides a new protocol for constructing efficient flexible photocatalysts for application in environmental remediation.

Heterojunction Architecture of N-Doped WO3 Nanobundles with Ce2S3 Nanodots Hybridized on a Carbon Textile Enables a Highly Efficient Flexible Photocatalyst

Nanostructured Metal Sulfides: Classification, Modification Strategy, and Solar‐Driven CO 2 Reduction Application

Bi3TaO7/Ti3C2 heterojunctions for enhanced photocatalytic removal of water-borne contaminants.

We herein prepared defective Bi2O2CO3 microspheres via a simple nitric acid treatment method. Upon generation from Bi2O2CO3, electrons and holes were superbly separated with the existence of defects. Combined with the advantages of multiple scattering and reflection, a large surface area and increased range of visible‐light absorption, the defective Bi2O2CO3 dispalyed a high efficiency for the photodegradation of HCHO gases and methyl orange. The defective Bi2O2CO3 also possessed a superior stability, which is important for practical applications. This work opens up new opportunities for the design and fabrication of high‐activity Bi‐based photocatalysts for environmental protection.

Enhanced Efficiency of Electron–Hole Separation in Bi2O2CO3 for Photocatalysis via Acid Treatment

Ultrathin Bi2MoO6 Nanosheets for Photocatalysis: Performance Enhancement by Atomic Interfacial Engineering

https://chemistry-europe.onlinelibrary.wiley.com/doi/pdf/10.1002/cctc.201800653

Kunshan Li

Papers

An overview of advanced methods for the characterization of oxygen vacancies in materials

Bi3TaO7/Ti3C2 heterojunctions for enhanced photocatalytic removal of water-borne contaminants.

Enhanced Efficiency of Electron–Hole Separation in Bi2O2CO3 for Photocatalysis via Acid Treatment

Ultrathin Bi2MoO6 Nanosheets for Photocatalysis: Performance Enhancement by Atomic Interfacial Engineering

Cover Feature: Enhanced Efficiency of Electron–Hole Separation in Bi2O2CO3 for Photocatalysis via Acid Treatment (ChemCatChem 9/2018)