Topics in Catalysis最新文献

In the recent years, piezocatalysis process is attracting extensive attention as an emerging technology to remove persistent organic pollutants. Its advantage is that it relies on mechanical energy and is independent of electricity and light source, unlike electrocatalysis or photocatalysis processes. In this research, 2H-MoS₂/g-C₃N₄ heterojunction materials were successfully fabricated via the hydrothermal method and utilized as piezocatalyst in the treatment of Rhodamine B. This material exhibited a highly efficient piezo-catalyst effect, with the piezo-response amplitudes of 78.8 mV, almost doubled compared to 39.8 mV of 2H-MoS₂. The degradation of Rhodamine B by ultrasonic irradiation could reach 75.4% only after 5 s and then 94.9% in 60 s without light assistance. This ultra-rapid degradation rate is attributed to the electron–hole pairs and transfer of the charge-carriers on the surface of 2H-MoS₂ and g-C₃N₄ via S-scheme heterojunction model, which was confirmed by density functional theory study. The piezo-catalytic ability of the material can still be improved for better treatment of other organic pollutants in aqueous environment.

In biotechnological methods for biodegradation, the effectiveness of detoxifying xenobiotics and recalcitrant substances in soil and water has sparked significant interest. Our study takes a unique approach by focusing on immobilizing the white-rot fungus (WRF) Pleurotus sajor-caju onto a Luffa cylindrica plant support. This innovative method aims to facilitate the mycoremediation of agro-industrial pollutant pulp wash generated by the orange industry. The immobilization process significantly increased MnP enzymatic activity, reaching 23 IU.mL⁻¹ and Lac activity at approximately 40.5 IU.mL⁻¹. Qualitative SEM and FTIR analyses provided insights into the microorganism’s attachment mechanism to the support, suggesting that aggregation occurs due to an affinity to the lignocellulosic structure, enhancing the production of polysaccharides responsible for biocatalyst adherence and potential reusability. Furthermore, the production of an enzymatic extract rich in ligninolytic enzymes from P. sajor-caju showcased its ability to reduce the toxicity of pulp wash. An exploration into the toxicity of citrus effluent revealed the generation of embryos with severe deformities and the inhibition of Lactuca sativa germination, even at low concentrations. Notably, post-treatment with the enzymatic extract resulted in a remarkable 90% reduction in toxicity to the trophic level of Danio rerio and lettuce seeds. This research significantly contributes to understanding fungal immobilization strategies in environmental biotechnology, emphasizing the potential of agricultural residues as sustainable inducers for enzyme production and their pivotal role in mitigating the environmental impact of agro-industrial waste.

Pollution from dye-containing industrial wastewater is a major health hazard in many nations, necessitating modern remediation approaches. Herein, zinc oxide (ZnO) was employed to degrade methyl orange (MO) as an organic dye pollutant under UV light irradiation. The performance was observed experimentally and theoretically under optimized conditions including the pH (11), the concentration of the nanoparticle solution (900 ppm), and time (3 h), resulting in a degradation efficiency of 89.6%. Furthermore, the influence of various parameters on MO degradation was evaluated by response surface methodology (RSM). X-ray diffraction (XRD) and transmission electron microscopy (TEM) was performed to investigate the crystallinity and morphological behavior of ZnO-NPs. In addition, the surface chemical composition was evaluated by the XPS analysis. This study evaluates the degradation efficiency of ~ 90% using single metal oxide to degrade MO, opening new opportunities for environmental applications.

Over time, industrialization, population expansion, building, and other human-related activities have made water contamination a major problem. As a result, steps towards waste water treatment must be taken. By using piezoelectric materials in the purifying process, a new area of waste water treatment known as piezo-photocatalysis has emerged. To improve the material’s water purification effectiveness, the piezoelectric action is paired with sun irradiation in this case. Up until this point, photocatalysis has served as a sophisticated method for purification. Thus, the piezoelectric materials became the center of attention in the quest for cutting-edge technologies for water purification. Piezoelectric materials have other potential applications outside of water treatment, including hydrogen production and carbon dioxide adsorption. The lead, barium, KNN, and bismuth perovskite compounds that have seen extensive usage in wastewater treatment are covered in this paper. These materials have the potential to achieve an efficiency of almost 100% when they combine the effects of piezoelectricity with photocatalysis. Consequently, the function of piezoelectric materials in wastewater treatment and the mechanism of piezo-photocatalysis are covered extensively in this paper.

The TiO₂ nanomaterial is a traditional photocatalyst that was applied externally in environmental and energy fields. However, a large band gap of TiO₂ is a limitation of this material in applications in visible-light regions. Sulfur (S) doped TiO₂ nanotubes were synthesized with different weight ratios of the S precursor and TiO₂ nanotubes by a thermal diffusion process. Techniques including Fourier transform infrared (FTIR), UV-vis diffuse reflection spectroscopy (DRS), photoluminescence spectroscopy (PL), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) were used to confirm the successful doping of the S-TiO₂ nanotubes. The treatment of nitrogen oxide (NO_x) gas through photocatalysis using S-doped TiO₂ nanotubes represents an innovative and environmentally friendly approach. Sulfur doping narrows the band gap of TiO₂ nanotubes (from 3.22 to 3.14 eV), allowing for better absorption of visible light. Furthermore, the photocatalytic NO_x removal performance of S-TiO₂ nanotubes was significantly enhanced with more than 40% NO at 500 ppb, and the efficiency of NO emission decreased significantly after five cycling tests.