Water pollution has become an increasingly serious global problem. The types of organic pollutants in water bodies are becoming more and more complex and diversified, which brings great challenges to environmental protection. In this paper, oxygen vacancy-rich nickel ferrite (NiFOV) was simply prepared by two methods (hydrothermal and calcination). The synergic effect of photocatalysis and peroxydisulfate (PDS) on the degradation of tetracycline hydrochloride (TCH) by NiFOV was studied. The results showed that NiFOV displayed excellent catalytic activity, the efficiency of degrading TCH within 60 min reached 87.4 %. In addition, NiFOV showed good stability and reusability, maintaining a degradation rate of 78.3 % after 4 cycles. Radical capture and electron paramagnetic resonance (EPR) experiments showed that possible degradation pathways included free radical pathway and non-free radical pathway, in which SO4 center dot(-), O-1(2), h(+) and center dot OH played important roles. The presence of oxygen vacancies significantly increased the specific surface area of the catalyst, enhanced the adsorption capability of O-2 and promoted the utilization of visible light and the activation of PDS. This study provides a new understanding of PDS activation based on ferrite defect engineering and has a good application prospect.

Ammonia has a wide range of applications in industry, agriculture, and energy storage. However, the Haber-Bosch synthesis of ammonia used in industry requires a high-temperature and high-pressure catalytic environment. In this study, the catalyst Bi5O7I/g-C3N4 was prepared through a simple calcination method, leveraging the unique layered structure and suitable band gap of Bi5O7I. Plasma technology was employed to activate nitrogen, converting inert N2 into more reactive NOx- intermediates, significantly reducing the reaction energy requirements. The presence of oxygen vacancies in the catalyst was found to lower the valence band energy, narrow the band gap, and extend the light absorption range, while also serving as active sites for the catalytic process. Moreover, the heterojunction structure of Bi5O7I/g-C3N4 enhanced the separation of photogenerated electron-hole pairs, improving carrier transport and enabling the participation of high-reduction potential electrons in ammonia synthesis. As a result, the catalyst achieved an ammonia yield of 59.09 mmol h-1 gcat.-1 and a Faraday efficiency of 20.09% in 0.1 M KOH under ambient conditions. This work highlights the use of abundant air and water as feedstocks and demonstrates an efficient, low-cost approach to ammonia synthesis.

Photoelectrocatalytic (PEC) could effectively and gently treat wastewater. Nonetheless, catalysts face the pronounced tendency of sluggish photogenerated carrier transfer and carrier recombination. In this paper, we herein fabricate FeOOH/BiVO 4 photoanode through the incorporation of a cocatalyst FeOOH onto the BiVO 4 surface. This modified photoanode demonstrated improved performance when coupled with peroxomonosulfate (PMS) for the purpose of oxidizing tetracycline hydrochloride (TCH) within the PEC system. In the presence of 0.3 mM PMS, the degradation efficiency of TCH increased from 65 % to 88 % within 60 min. The effects of PMS concentration, applied voltage and TCH concentration on the decomposition were studied in detail. Through free radical scavenging experiments, it was found that SO 4 center dot- , h + and & sdot;OH played an important role in TCH degradation. In addition, the FeOOH/BiVO 4 with PMS activation in the PEC system also could be capable of dealing with some more organic pollutants (antibiotics and dyes) and achieving good degradation effect. More importantly, TCH degradation rate by FeOOH/BiVO 4 photoanode is still over 80 % after five cycles of reuse. This work provides a promising approach for the synthesis of novel photoanodes in the PEC systems with excellent PEC properties in removing environmental pollutants.

With the abuse of antibiotics, its pollution poses an increasing threat to the environment and human health. Effective degradation of organic pollutants in water bodies is urgent. Compared to traditional treatment methods, advanced oxidation processes that have developed rapidly in recent years are more environmentally friendly, efficient and applicable to a wider range of organic compounds. FeWO4 was used in this study as the iron-based semiconductor material to modify and optimize the material design. Fe3O4/FeWO4 composites were prepared by a two-step hydrothermal method. The crystal structure, surface morphology, electrochemical properties and separability of the composite semiconductor were analyzed by XRD, XPS, UV-vis, SEM, EDS and Mott-Schottky. The results showed that, when the initial contaminant concentration was 30 mg/L, the initial solution pH was 4, the dosage of the catalyst was 25 mg and the dosage of hydrogen peroxide was 30 μL, the degradation efficiency of tetracycline hydrochloride (TCH) could reach 91% within 60 min, which was significantly improved compared to the performance of the single semiconductors Fe3O4 and FeWO4. In addition, the catalyst prepared in this experiment can be easily recovered by magnetic separation technology in practical application, which will not affect the turbidity of water while reducing the cost of catalyst separation and recovery.

A La2Ti2O7/acid-modified coal-bearing strata kaolinite (La2Ti2O7/AK) composite was successfully prepared using a simple hydrothermal method. The composite prepared was used in the selective adsorption and photocatalytic degradation system of chlortetracycline hydrochloride (CTC center dot HCl). This system demonstrated the successful preparation of La2Ti2O7/AK, a large amount of active space, and excellent photoelectric properties, which contributed to the adsorption and photocatalytic degradation of CTC center dot HCl by La2Ti2O7/AK. The results demonstrates that the prepared composite has excellent selective adsorption performance for CTC center dot HCl in a single solution at pH = 4 but poor selective adsorption performance for CTC center dot HCl in binary solutions (CTC center dot HCl/TCH and CTC center dot HCl/OTC). Furthermore, the effects of the solution pH, material types, and inorganic ions on CTC center dot HCl adsorption are attributed to the synergistic effect of various adsorption mechanisms. Moreover, the free radical capture and electron paramagnetic resonance (EPR) experiments confirmed that the main free radicals for photocatalytic degradation are center dot O2-, OH, and h(+). Finally, the adsorption and photocatalytic degradation efficiency of La2Ti2O7/AK in case of CTC center dot HCl in wastewater remained at > 70 %. Therefore, its excellent adsorption, unique selectivity, excellent photocatalytic degradation, wide applicability, and outstanding stability in wastewater make it an ideal catalyst for the selective adsorption and photocatalytic degradation of CTC center dot HCl from complex wastewater.

低能见度很大程度上影响着车辆行驶安全,本文主要阐述了一种低能见度下车辆雾灯自动开启的装置及方法,该研究的推广可以减少低能见度下公路交通安全事故发生的概率.

论文首先将公交车运行过程分为路段、交叉口以及停靠站三个阶段,并分别对各个阶段的速度资料进行统计分析,总结出公交车运行速度特性.然后,基于层次分析法,以公交运行速度、公交运行速度变差系数、公交平均运行速度与设计速度之差三个指标建立了公交运行速度的安全评价准则,得到了公交车运行速度的安全等级,这对于公交车的车速安全管理具有一定的理论和指导意义.