Electrodeposition of PbO2 and Bi–PbO2 on Ebonex

Electrodeposition of PbO2 and Bi–PbO2 on Ebonex was carried out under various conditions, and the surfaces and coating/substrate interfaces examined by SEM, XPS and SIMS. Excellent adhesion to Ebonex was obtained with both crystalline and amorphous surfaces. Low plating temperatures resulted in dark grey, bright PbO2 and black, mirror-like Bi–PbO2 surfaces. Extrapolation of electrode lifetime test data indicated corrosion rates of 716 m yr–1 for PbO2 and 158 m yr–1 for Bi–PbO2.     

Investigation of the photodecomposition of phenol in near-UV-irradiated aqueous TiO2 suspensions. I: Effect of charge-trapping species on the degradation kinetics

The effects of charge-trapping species on the kinetics of phenol decomposition were studied in near-UV-irradiated aqueous TiO₂ (anatase) suspensions in a batch photoreactor. The influence of catalyst loading, initial phenol concentration, dissolved O₂ concentration, Ag⁺ content and H₂O₂ concentration on the rate of phenol degradation is reported. The observed heterogeneous degradation of phenol followed apparently zero-order kinetics up to ca. 70% conversion. The Langmuir–Hinshelwood kinetic model successfully described the influence of the initial phenol concentration and dissolved O₂ concentration on the rate of heterogeneous photooxidation of phenol. The data obtained by applying the Langmuir–Hinshelwood treatment are consistent with the available kinetic parameters. The results of the experiments in the presence of Ag⁺ indicated that the phototransformation of phenol can proceed via direct electron transfer, neither dissolved O₂ nor its reduction forms playing a significant role in the degradation mechanism.     

Modelling of the kinetic of 2-chlorophenol catalytic photooxidation

The photoassisted oxidation of dilute aqueous solutions of 2-chlorophenol (2-CP) is investigated over a solid catalyst (TiO₂) at laboratory level in an annular photocatalytic reactor. In order to characterise the reaction, different kinetic models are proposed, being related to the attack of the reagent by ^.OH radicals. The model based on the competitive adsorption between oxygen and 2-chlorophenol does not lead to satisfactory results. For the other models it was assumed that oxygen adsorption occurs at different sites. The model with the adsorption isotherms of reagent and oxygen being proposed of a Langmuir type is the only one able to justify the observed dependence of the pollutant disappearance rate on dissolved 2-CP concentration, oxygen partial pressure and absorbed light intensity with adsorption parameters deduced from direct measurements.     

Electrochemical reduction of carbon dioxide to ethylene with high Faradaic efficiency at a Cu electrode in CsOH/methanol

The electrochemical reduction of CO₂ with a Cu electrode in CsOH/methanol-based electrolyte was investigated. The main products from CO₂ were methane, ethylene, ethane, carbon monoxide and formic acid. A maximum Faradaic efficiency of ethylene was 32.3% at −3.5 V vs. Ag/AgCl saturated KCl. The best methane formation efficiency was 8.3% at −4.0 V. The ethylene/methane current efficiency ratio was in the range 2.9–7.9. In the CsOH/methanol, the efficiency of hydrogen formation, being a competitive reaction against CO₂ reduction, was depressed to below 23%.     

热处理工艺对TiO2纳米薄膜光催化性能的影响

通过ｓｏｌ－ｇｅｌ工艺在玻璃表面制备了均匀透明的锐钛矿型ＴｉＯ２钠米光催化薄膜,ＴｉＯ２薄膜由３０￣１００ｎｍ的球形颗粒组成,每镀一次薄膜的厚度增加约０．０８μｍ,薄膜中出现的锐钛矿在（１０１）面具有一定的择优取向,薄膜中除含有Ｔｉ,Ｏ,Ｃ等元素外,还存在少量从玻璃表面扩散到薄膜中的Ｎａ和Ｃａ元素,甲基 橙水溶液的光催化降解实验表明：当薄膜经５００℃,ｌｈ在空气中热处理后,薄膜表观反应速度常数ｋ为     

包核钛白颜料生产的技术原理及发展方向

介绍了包核钛白颜料技术原理、国内包核钛白的技术现状及发展方向。     

硫酸法钛白生产中的废硫酸治理

探讨了硫酸法钛白生产中的废硫酸治理。采用一次浓缩和化学方法将２０ ％ 废硫酸制备相关的化工产品;采用石灰中和法治理１ ％ 废硫酸,达到较为理想的治理效果。     

硫磺汽化管失效原因及对策

通过对原高温硫磺汽化管失效原因的分析,提出了改进管子化学成分的方案,实践证明这一方案是有效的。     

合成氨常解气在碳酸钡生产中的应用

阐述了碳酸钡的生产过程和控制及彩和合成氨常解气对生产过程的影响,并对解决这些问题提出相应的对策。     

脱除SO2的催化方法研究进展

综述了各种脱除二氧化硫的催化方法,比较了其优缺点,着重介绍了复合金属氧化物脱硫的研究进展和发展方向。