Photoreduction of N₂ is among the most interesting and challenging methods for N₂ fixation under mild conditions. In this study, we determined that nitrogen vacancies (NVs) could endow graphitic carbon nitride (g-C₃N₄) with the photocatalytic N₂ fixation ability. Photocatalytic N₂ fixation induced by NVs is free from the interference of other gases. The reason is that NVs could selectively adsorb and activate N₂ because NVs have the same shape and size as the nitrogen atom in N₂. In addition to this, NVs could also improve many other properties of g-C₃N₄ to support photocatalytic N₂ fixation. These new findings could elucidate the design of efficient photocatalysts for photocatalytic N₂ fixation.

Selective photocatalytic N₂ fixation dependent on g-C₃N₄ induced by nitrogen vacancies

2D materials show many particular properties, such as high surface‐to‐volume ratio, high anisotropic degree, and adjustable chemical functionality. These unique properties in 2D materials have sparked immense interest due to their applications in photocatalytic systems, resulting in significantly enhanced light capture, charge‐transfer kinetics, and surface reaction. Herein, the research progress in 2D photocatalysts based on varied compositions and functions, followed by specific surface modification strategies, is introduced. Fundamental principles focusing on light harvesting, charge separation, and molecular adsorption/activation in the 2D‐material‐based photocatalytic system are systemically explored. The examples described here detail the use of 2D materials in various photocatalytic energy‐conversion systems, including water splitting, carbon dioxide reduction, nitrogen fixation, hydrogen peroxide production, and organic synthesis. Finally, by elaborating the challenges and possible solutions for developing these 2D materials, the review is expected to provide some inspiration for the future research of 2D materials used on efficient photocatalytic energy conversions.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adma.202200180

Surface Modification of 2D Photocatalysts for Solar Energy Conversion

Polyoxometalate@Metal–Organic Framework Composites as Effective Photocatalysts

Fabrication of fibrous MXene nanoribbons (MNRs) membrane with efficient performance for oil-water separation

A critical review on graphitic carbon nitride (g-C3N4)-based composites for environmental remediation

Delicate fabrication grounded on 2D epitaxial heterostructure can be identified as an available strategy to sufficiently discover and utilize its preponderances. Herein, bismuth sulfide-bridged Bi2S3/sulfuretted ZnAl-LDHs (Bi2S3/ZnAlSx) heterojunctions were rationally designed and fabricated via simple ion-exchange and hydrothermal treatment methods. The photocatalytic activities of the heterojunction composites were evaluated for the degradation of tetracycline (TC) under visible-light irradiation. Compared to the ZnAl-LDHs and ZnAlSx, the composites showed the best visible-light-driven photocatalytic performance for TC degradation due to the intimate contact between ZnAlSx and Bi2S3. In additional, upon the proper weight ratio of Bi2S3 (20 wt%), the as-synthesized production exhibited the highest photodegradation efficiency for TC (90.89%) under visible-light irradiation. Surprisingly, the apparent reaction rate constant (k) of Bi2S3/ZnAlSx is approximately 3.3-folds higher than ZnAlSx. Moreover, the possible reaction mechanism of the enhanced photocatalytic activity was proposed resulting from inhibited the recombination between photogenerated electrons and holes. Additionally, the 20 wt% Bi2S3/ZnAlSx showed the high removal efficiency (80.18%) for TC pollutants after four continuous cycles. This work underlines the important of heterostructure construction and further testifies that bismuth sulfide-bridged Bi2S3/sulfuretted ZnAl-LDHs (Bi2S3/ZnAlSx) are promising photocatalysts for the decomposition of antibiotics from waste water under visible-light irradiation.

Bismuth sulfide bridged Bi2S3/sulfuretted ZnAl-LDHs heterojunctions for synergetic enhancement of photodegradation activity towards tetracycline degradation

The construction of a photocatalyst with a heterostructure for the photocatalytic degradation of antibiotics in wastewater is considered as an ecofriendly and promising strategy. Herein, the two-dimensional NiAl-LDH nanosheets were uniformly grown on the (BiO)2CO3 matrix, successfully forming a series of Z-scheme heterojunction NiAl-LDH/(BiO)2CO3 photocatalysts. When the mass fraction of (BiO)2CO3 achieved 25%, the prepared heterojunction photocatalyst exhibits superior performance (0.01193 min–1) and excellent stability (five cycles) for photocatalytic degradation of tetracycline. Moreover, the prepared heterojunction had a faster degradation rate in a natural water body, which indicated its excellent practicability. Due to the matched energy bands, Z-scheme heterojunctions were formed between two semiconductors. The Z-scheme heterojunction can effectively promote the separation efficiency of photogenerated charge-hole pairs and generate more active electrons and holes, therefore providing more radicals and active sites for photocatalytic reactions. This work is expected to be used to remove antibiotics from actual water bodies. 

Construction of a Novel Visible-Light-Driven Z-Scheme NiAl-LDH Modified (BiO)2CO3 Heterostructure for Enhanced Photocatalytic Degradation Antibiotics Performance in Natural Water Bodies

Halogen doped g-C3N4/ZnAl-LDH hybrid as a Z-scheme photocatalyst for efficient degradation for tetracycline in seawater

Photocatalytic degradation holds great promise for addressing the growing threat of antibiotics residues in aquatic environments. The internal electric field (IEF) can significantly enhance the photocatalytic performance by efficient separation...

Building Internal Electric Fields in porous ionic polymers for fast photocatalytic degradation of tetracycline hydrochloride

Preparing photocatalysts with excellent performance to degrade organic pollutants in water is still a great challenge. Herein, we prepared CoAl-layered double hydroxide (LDH) coupled N-rich carbon nitride of C3N5 materials to investigate the feasibility of preparing materials for photocatalytic treatment of organic pollutants under natural water bodies. After 120 min of light exposure, the CoAl-LDH/C3N5 (CCN-100) composite showed optimal photocatalytic degradation performance, in which the degradation efficiency reached 94.02% in pure water and 91.85% in Xiangjiang water. Three possible photocatalytic degradation pathways of tetracycline were analyzed by liquid chromatography with tandem mass spectrometry. The toxicity of the intermediates was assessed by toxicity assessment software. The results showed that the toxicity of the intermediates was greatly reduced. We analyzed the formation of the internal electric field and the direction of charge migration in the CoAl-LDH/C3N5 heterojunction by the difference in the work function and the energy band structure of CoAl-LDH and C3N5. According to various characterization analysis and experimental results, the internal electric field formed between CoAl-LDH and C3N5 accelerates the charge transfer and the rapid separation of photogenerated electron holes thus improving the photocatalytic degradation performance. This study provides new insights into the effective removal of organic pollutants from water through the formation of an internal electric field in CoAl-LDH/C3N5 heterojunction. 

Jun Hu

Papers

Bismuth sulfide bridged Bi2S3/sulfuretted ZnAl-LDHs heterojunctions for synergetic enhancement of photodegradation activity towards tetracycline degradation

Construction of a Novel Visible-Light-Driven Z-Scheme NiAl-LDH Modified (BiO)2CO3 Heterostructure for Enhanced Photocatalytic Degradation Antibiotics Performance in Natural Water Bodies

Halogen doped g-C3N4/ZnAl-LDH hybrid as a Z-scheme photocatalyst for efficient degradation for tetracycline in seawater

Building Internal Electric Fields in porous ionic polymers for fast photocatalytic degradation of tetracycline hydrochloride

Internal Electric-Field-Driven CoAl-LDH Coupled N-Rich Carbon Nitride of C3N5 for Improved Photocatalytic Performance