Xuepeng Wang

The widespread deployment of photocatalytic technology still remains limited by its dependence on high‐purity gas inputs and specialized light sources. Achieving high efficiency under these conditions calls for rational structural design of photocatalysts. Here, we report a one‑precursor synthesis of graphitic carbon nitride (g‑C ₃ N ₄ ) featuring edge‑localized p‑π conjugation, using cyanuric acid alone, for efficient photocatalytic H ₂ O ₂ production in air. The degree of p‑π conjugation is regulated via hydroxyl group content, which is controlled by special calcination conditions. This conjugation promotes charge transfer by extending electron delocalization and prolonging exciton lifetime, while also strengthening O ₂ adsorption to facilitate mass exchange. As a result, the synergistically optimized p‑π conjugated g‑C ₃ N ₄ prepared at 450°C achieves an H ₂ O ₂ photosynthesis rate of 3588 µmol g ⁻¹ h ⁻¹ under laboratory air and visible light, representing a 7.2‑fold enhancement over pristine g‑C ₃ N ₄ . Under natural sunlight outdoors, the rate further rises to 8845 µmol g ⁻¹ h ⁻¹ . This work provides a feasible structural engineering strategy to advance the practical application of photocatalytic H ₂ O ₂ generation.

Prolonged photoreduction of NO ₃ ⁻ leads to linker deficiency, thereby resulting in agglomeration of Ti ³⁺ sites in MIL-125, causing a negative shift in the conduction band potential, and increasing the reaction barrier.

Introducing a sulfone group into COF structure induces electron accumulation and separated redox centers for efficient water oxidation and oxygen reduction reaction, thus accelerating the overall photocatalytic H ₂ O ₂ synthesis in pure water.

Conjugated polymers (CPs) have shown promising potential in the field of hydrogen peroxide (H₂O₂) photosynthesis. However, a deeper understanding of the interactions between building units and specific functional groups within the molecular skeleton is necessary to elucidate the mechanisms driving H₂O₂ generation. Herein, a series of typical donor‐acceptor (D‐A) conjugated polymers (B‐B, B‐CN, B‐DCN) were synthesized by introducing different amounts of cyano groups (‐CN) into the molecular skeleton. The strong electron withdrawing properties of cyano can greatly promote the effective separation and transfer of photogenerated charges between building units, resulting in an impressive efficiency of H₂O₂ generation (2128.5 μmol g⁻¹ h⁻¹) for B‐DCN, representing a 96‐fold enhancement compared to B‐B. More importantly, experimental results and theoretical calculations further revealed that the introduction of ‐CN can markedly reduce the adsorption energy (E_ad) of O₂, while serving as an active site to induce the conversion of crucial intermediate superoxide anions (⋅O₂⁻) into singlet oxygen (¹O₂), achieving dual‐channel H₂O₂ generation (O₂→⋅O₂⁻→H₂O₂, O₂→⋅O₂⁻→¹O₂→H₂O₂). This work provides valuable insights into the design of efficient H₂O₂ photosynthesis materials.

Graphite carbon nitride (g‐C₃N₄) nanotubes have received extensive attention due to its unique morphology and electronic migration. Herein, the defective porous g‐C₃N₄ nanotube (DTCN) is prepared through a simple thermal reduction process. The construction of N vacancy and tubular structure can synergistically promote the separation of photogenerated charge carriers. As a result, DTCN demonstrates a higher photocatalytic hydrogen evolution rate (1440 μmol·g⁻¹·h⁻¹), which is 5 times higher than that of the initial g‐C₃N₄ nanotube (TCN). Importantly, combined with density functional theory calculations and experimental results, it is the first time to prove that the synergy of curvature effect and N vacancy of nanotubes can enhance the adsorption energy of hydrogen and decrease the work function, resulting in more superior photocatalytic performance than the layered structure. This work provides more in‐depth comprehension for the photocatalytic mechanism of nanotube materials, which has inspirational significance for the design of the g‐C₃N₄ photocatalyst with high performance.

C ₄ N quantum dots/g-C ₃ N ₄ nanosheets composites are prepared via self-assembly process, which show excellent photocatalytic H ₂ production, 2 times than original g-C ₃ N ₄ nanosheets due to narrow band gap and unique band structure of C ₄ N quantum dots.

Photocatalytic elimination of antibiotics from the environment and drinking water is of great significance for human health. However, the efficiency of photoremoval of antibiotics such as tetracycline is severely limited by the prompt recombination of electron holes and slow charge migration efficacy. Fabrication of low-dimensional heterojunction composites is an efficient method for shortening charge carrier migration distance and enhancing charge transfer efficiency. Herein, 2D/2D mesoporous WO₃/CeO₂ laminated Z-scheme heterojunctions were successfully prepared using a two-step hydrothermal process. The mesoporous structure of the composites was proved by nitrogen sorption isotherms, in which sorption-desorption hysteresis was observed. The intimate contact and charge transfer mechanism between WO₃ nanoplates and CeO₂ nanosheets was investigated using high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy measurements, respectively. Photocatalytic tetracycline degradation efficiency was noticeably promoted by the formation of 2D/2D laminated heterojunctions. The improved photocatalytic activity could be attributed to the formation of Z-scheme laminated heterostructure and 2D morphology favoring spatial charge separation, confirmed by various characterizations. The optimized 5WO₃/CeO₂ (5 wt.% WO₃) composites can degrade more than 99% of tetracycline in 80 min, achieving a peak TC photodegradation efficiency of 0.0482 min⁻¹, which is approximately 3.4 times that of pristine CeO₂. A Z-scheme mechanism is proposed for photocatalytic tetracycline by from WO₃/CeO₂ Z-scheme laminated heterojunctions based on the experimental results.

Titanium dioxide (TiO₂) nanomaterials have been widely used in photocatalytic energy conversion and environmental remediation due to their advantages of low cost, chemical stability, and relatively high photo-activity. However, applications of TiO₂ have been restricted in the ultraviolet range because of the wide band gap. Broadening the light absorption of TiO₂ nanomaterials is an efficient way to improve the photocatalytic activity. Thus, black TiO₂ with extended light response range in the visible light and even near infrared light has been extensively exploited as efficient photocatalysts in the last decade. This review represents an attempt to conclude the recent developments in black TiO₂ nanomaterials synthesized by modified treatment, which presented different structure, morphological features, reduced band gap, and enhanced solar energy harvesting efficiency. Special emphasis has been given to the newly developed synthetic methods, porous black TiO₂, and the approaches for further improving the photocatalytic activity of black TiO₂. Various black TiO₂, doped black TiO₂, metal-loaded black TiO₂ and black TiO₂ heterojunction photocatalysts, and their photocatalytic applications and mechanisms in the field of energy and environment are summarized in this review, to provide useful insights and new ideas in the related field.