Constructing h-BN/Bi2 WO6 Quantum Dot Hybrid with Fast Charge Separation and Enhanced Photoelectrochemical Performance by using h-BN for Hole Transfer

Construction of dual transfer channels in graphitic carbon nitride photocatalyst for high-efficiency environmental pollution remediation: Enhanced exciton dissociation and carrier migration

Graphitic carbon nitride (g-C₃N₄) is a promising candidate for photocatalysis, but exhibits moderate activity due to strongly bound excitons and sluggish charge migration. The dissociation of excitons to free electrons and holes is considered an effective strategy to enhance photocatalytic activity. Herein, a novel boron nitride quantum dots (BNQDs) modified P-doped g-C₃N₄ photocatalyst (BQPN) was successfully prepared by thermal polymerization method. Photoluminescence techniques and photoelectrochemical tests demonstrated that the introduction of P atoms and BNQDs promoted the dissociation of excitons and the migration of photogenerated carriers. Specifically, theoretical calculations revealed that P substitutions were the sites of pooled electrons, while BNQDs were the excellent photogenerated hole extractors. Accordingly, compared with g-C₃N₄, the BQPN showed improved performance in degrading four non-steroidal anti-inflammatory drugs (NSAIDs) under visible light irradiation. This work not only establishes an in-depth understanding of excitonic regulation in g-C₃N₄, but also offers a promising photocatalytic technology for environmental remediation.

Cytotoxic and photocatalytic studies of hexagonal boron nitride nanotubes: a potential candidate for wastewater and air treatment

Boron nitride (BN) nanomaterials are rapidly being investigated for potential applications in biomedical sciences due to their exceptional physico-chemical characteristics. However, their safe use demands a thorough understanding of their possible environmental and toxicological effects. The cytotoxicity of boron nitride nanotubes (BNNTs) was explored to see if they could be used in living cell imaging. It was observed that the cytotoxicity of BNNTs is higher in cancer cells (65 and 80%) than in normal cell lines (40 and 60%) for 24 h and 48 h respectively. The influence of multiple experimental parameters such as pH, time, amount of catalyst, and initial dye concentration on percentage degradation efficiency was also examined for both catalyst and dye. The degradation effectiveness decreases (92 to 25%) as the original concentration of dye increases (5-50 ppm) due to a decrease in the availability of adsorption sites. Similarly, the degradation efficiency improves up to 90% as the concentration of catalyst increases (0.01-0.05 g) due to an increase in the adsorption sites. The influence of pH was also investigated, the highest degradation efficiency for MO dye was observed at pH 4. Our results show that lower concentrations of BNNTs can be employed in biomedical applications. Dye degradation properties of BNNTs suggest that it can be a potential candidate as a wastewater and air treatment material.

Bi2WO6 Semiconductor Nanoplates for Tumor Radiosensitization through High- Z Effects and Radiocatalysis

The radioresistance of tumor cells is considered to be an Achilles' heel of cancer radiotherapy. Thus, an effective and biosafe radiosensitizer is highly desired but hitherto remains a big challenge. With the rapid progress of nanomedicine, multifunctional inorganic nanoradiosensitizers offer a new route to overcome the radioresistance and enhance the efficacy of radiotherapy. Herein, poly(vinylpyrrolidone) (PVP)-modified Bi₂WO₆ nanoplates with good biocompatibility were synthesized through a simple hydrothermal process and applied as a radiosensitizer for the enhancement of radiotherapy for the first time. On the one hand, the high- Z elements Bi ( Z = 83) and W ( Z = 74) endow PVP-Bi₂WO₆ with better X-ray energy deposition performance and thus enhance radiation-induced DNA damages. On the other hand, Bi₂WO₆ semiconductors exhibit significant photocurrent and photocatalytic-like radiocatalytic activity under X-ray irradiation, giving rise to the effective separation of electron/hole (e^-/h⁺) pairs and subsequently promoting the generation of cytotoxic reactive oxygen species, especially hydroxyl radicals (^•OH). The γ-H2AX and clonogenic assays demonstrated that PVP-Bi₂WO₆ could efficiently increase cellular DNA damages and colony formations under X-ray irradiation. These versatile features endowed PVP-Bi₂WO₆ nanoplates with enhanced radiotherapy efficacy in animal models. In addition, Bi₂WO₆ nanoplates can also serve as good X-ray computed tomography imaging contrast agents. Our findings provide an alternative nanotechnology strategy for tumor radiosensitization through simultaneous radiation energy deposition and radiocatalysis.

Enhanced charge separation and increased oxygen vacancies of h-BN/OV-BiOCl for improved visible-light photocatalytic performance

h-BN/OV-BiOCl composites were prepared to improve the visible-light photocatalytic activity of OV-BiOCl.

Visible Light-Responsive Photocatalytic Activity of Boron Nitride Incorporated Composites

Photocatalysts are essential to promote the highly efficient applications of solar energy in water splitting and/or the degradation of organic contaminations. Especially, the visible light-responsive photocatalysts could benefit with the cost-effective splitting or degradation due to the unlimited sunlight and the absence of expensive light emitter. In the photocatalysts, the charge transfer rates as well as the hole-electron recombination rate are two critical factors that determine the photocatalytic activity, which could also be affected by the dimension, defects, doping and morphologies controlled by the synthesis methods. Boron nitride (BN) is an ultrawide-bandgap semiconductor, and the combination of BN with the visible light-responsive photocatalysts has been found to be effective in enhancing the photocatalytic activities. Therefore, it should be meaningful to understand the BN incorporated photocatalytic composites in depth, including the synthetic approaches, the activity improving mechanisms and the versatile applications. In this review, we mainly focused on the assembly method of BN incorporated photocatalysts; the activity enhancing mechanism by introducing the BN in the photocatalytic composites as well as the properties and the applications. In the end, we gave a conclusion and an outlook for the BN incorporated photocatalytic composites.