Baoyan Liang

This study employed a complex tin hydroxychloride compound [Sn₂₁Cl₁₆(OH)₁₄O₆] as a precursor to achieve the one-step synthesis of SnO₂ nanocomposites via a low-temperature solid-liquid reaction method under ambient pressure. By adjusting the mass ratio of the sulfur source (Na₂S·5H₂O) to the precursor (1 : 0.5–1 : 2), the phase composition of the product could be tuned from a SnS/SnO₂ mixed phase to a pure SnO₂ phase, effectively controlling the material’s microstructure. The synthesized SnO₂ nanocrystals were smaller than 10 nm, with a specific surface area of 127.74 m²/g, and an optical band gap of approximately 3.63 eV, exhibiting a typical mesoporous structure and broad-spectrum photoresponse. This method features a low reaction temperature (84°C) and a simple process, providing an efficient and controllable route for the low-temperature, energy-saving synthesis of SnO₂ nanomaterials.

Nano Al ₂ O ₃ /reduced graphene oxide (rGO) composites were directly synthesized by one simple low-temperature heat treatment using nano Al ₂ O ₃ and GO powders as raw materials. The degradation capability of the samples to methylene blue (MB) was tested under simulated sunlight. Results show that heating at a low temperature can induce a reduction reaction in GO and facilitate its transformation into rGO. Simultaneously, rGO may be fully composited with nano Al ₂ O ₃ to obtain Al ₂ O ₃ /rGO composites. The addition of GO markedly enhances the light absorption capacity of the samples in the entire light region. The fluorescence spectrum intensity of the sample can be reduced by adding proper amounts of GO. The obtained sample exhibited the best simulated solar photocatalytic activity when the amount of GO added was 15wt%, and MB was degraded within 60 min.

Sn₃OSO₄(OH)₂ was successfully synthesized using a simple solid-state reaction method. The material was applied to the photocatalytic degradation of industrial dyes. Experimental results indicated that the material could be rapidly synthesized through a straightforward vibration treatment of NaOH and SnSO₄ powders for 5 min. Its average particle size was 14 μm. The BET value was 1.32 m²/g. It had stronger light absorption ability in visible regions. Sn₃OSO₄(OH)₂ exhibited good photocatalytic performance under UV and simulated sunlight irradiation. It could completely degrade methyl orange in 92 and 45 min under the two conditions, respectively. Finally, a mechanism of photocatalytic degradation of MO by Sn₃OSO₄(OH)₂ was proposed.

In this study, an efficient SnO₂ photocatalyst was rapidly synthesized via a simple solid-state reaction method using SnSO₄ and hydrogen peroxide disinfectant (with solid hydrogen peroxide powder as the reactant). The results indicate that the formation of SnO₂ occurs rapidly after heating the mixed powder to approximately 80°C, with a reaction time of approximately 30 s. XRD analysis reveals poorly developed crystal grains with fine sizes. SEM and TEM observations confirmed that the sample was composed of numerous nanocrystallites. Infrared spectroscopy reveals the presence of abundant hydroxyl groups in the sample. XPS characterization confirms the presence of sulfur doping in SnO₂. UV-Vis absorption spectroscopy demonstrates that sulfur-doped SnO₂ exhibited good light absorption in the visible region and a reduction in the bandgap energy. Photoluminescence spectroscopy indicates that sulfur doping increased oxygen vacancies, promoting the separation of photogenerated electrons and holes. The prepared sulfur-doped SnO₂ catalyst exhibited outstanding photocatalytic degradation capabilities. The optimal sample completely degrades methyl orange within 90 min under visible light or 6 minutes under sunlight. Finally, a mechanism for the photocatalytic degradation of methyl orange by sulfur-doped SnO₂ was proposed.

This study proposes a method for using thermal explosion to coat the surfaces of diamond particles quickly. This method utilizes the high temperature generated by thermal explosion to promote the rapid sublimation and deposition of Ti powder on the surfaces of diamond particles. This study applied a mixed powder of Ti and diamond particles and conducted vacuum heat treatment. Ni–Al compacts were used for thermal explosion to promote the rapid sublimation and deposition of Ti on the surfaces of diamond particles. Results indicate that Ti rapidly evaporated and deposited on the surfaces of diamond particles after thermal explosion. A composite coating of Ti and TiC on the surfaces of diamond particles formed. The compressive fracture strength and impact toughness index of the prepared Ti–TiC coated diamond particles were 16.0% and 7.4% higher than those of the original diamond particles, respectively.

ZnO/Zn₃N₂ composites were prepared through rapid heat treatment using Zn(OH)₂ and C₃N₄ raw materials. This study investigated the effects of varying raw material ratios on the phase composition, microscopic morphology, and photocatalytic properties of the resulting products. The results demonstrated that Zn(OH)₂ decomposed rapidly into ultrafine ZnO grains at 800°C. Subsequently, the newly generated ZnO reacted with C₃N₄ to form ZnO/Zn₃N₂ composites. Notably, an increase in C₃N₄ content enhanced the composites’ light absorption capacity in the visible spectrum. Moderate additions (10 and 15%) of C₃N₄ significantly improved the photocatalytic degradation of methylene blue (MB). Specifically, the product containing 15% C₃N₄ exhibited optimal photocatalytic performance, achieving a degradation rate of 99.1% for MB within 20 min. Finally, one possible photocatalytic reaction mechanism for ZnO/Zn₃N₂ composites was proposed.

This research employed ozone modification technology to enhance the photocatalytic performance of ZnO. The findings indicated that ozone modification does not alter the crystal structure of ZnO. However, analyses using FTIR, XPS, and TEM revealed significant changes in the surface structure of the modified ZnO. Notably, the ability of the material to absorb visible light was improved, resulting in enhanced catalytic efficiency. Compared to unmodified ZnO, the ozone-modified ZnO demonstrated superior photocatalytic activity. Under simulated sunlight irradiation, the degradation efficiency of the ozone-assisted ultrasound-treated sample for methylene blue reached an impressive 99.6% within just 20 min, highlighting its promising application prospects.