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Kompleksowy przegląd metod preparatyki, właściwości i zastosowań fotokatalitycznych różnych struktur perowskitowych

Miodyńska Magdalena, Cavdar Onur, Pancielejko Anna

Wiadomości Chemiczne

2024

[Z] 78, 3-4

243--262

Perovskite materials for photocatalytic environmental and energy conversion applications have drawn excessive attention over recent years owing to their unique photoelectric and catalytic properties. As harvesting solar energy within the bounds of possibility is one of the main aims of photocatalysis, many research groups have devoted their efforts to developing perovskite-based photocatalytic materials from perovskite oxide to metal halide and double halide-based perovskite materials with various synthesis strategies. Particularly, halide and double halide-based perovskites are intriguing thanks to their tunable band gap and band structure depending on the type of halide. Apart from the obstacles related to charge separation and transport processes; instability under water, oxygen, and high temperature hindering their practical photocatalytic application are remaining challenges. Toxicity emerging from Pb2+ or Sn2+ release due to chemical instability is another concern to be tackled. Thusfar, replacing Pb2+ or Sn2+ with Bi3+ is one of the currentscopesin the perovskite photocatalysis area while ensuring chemical stability in halide-based perovskites and thus reducing toxicity. Despite all those challenges, the popularity of perovskite photocatalysis is growing amid the favorable light induced chemical reactions via a plentiful range of promising cost-effective manufacturing methods of perovskites. In this review, the principles and photocatalytic applications of the perovskite oxides, metal halide-based perovskites, and double halide-based are comprehensively discussed.

Effect of direct reduction time of vanadium titanomagnetite concentrate on the preparation and photocatalytic performance of calcium titanate

Li Xiaohui, Kou Jue, Sun Tichang, Wu Shichao, Tian Yuechao

Physicochemical Problems of Mineral Processing

2021

Vol. 57, iss. 1

75--86

Effects of direct reduction time of vanadium titanomagnetite concentrate (VTCE) on the preparation and photocatalytic performance of calcium titanate were investigated in this study. It was found that extending the reduction time could not only promote the formation of calcium titanate, but also facilitate the reduction of iron minerals in the reduction products. The optimum reduction time was 180min under the conditions of CaCO3 dosage of 18wt%, reduction temperature of 1400℃ and lignite dosage of 70wt%. The reduced iron (Fe grade of 90.95wt%, Fe recovery of 92.21wt%) and calcium titanate were obtained via grinding-magnetic separation. Moreover, calcium titanate prepared via the direct reduction method could be used as a photocatalyst, where the degradation degree of methylene blue increased from 25.13% to 60.14% with the addition of calcium titanate. Furthermore, Langmuir Hinshelwood fitting results indicated that the degradation of methylene blue by the calcium titanate prepared under different reduction times conformed to first-order reaction kinetics, where the photocatalytic degradation rate of methylene blue was noted to be the highest for a reduction time of 180 min.

Preparation, characterization and photocatalytic performances of materials based on CS2-modified titanate nanotubes

An H., Hu X., Zhu B., Song J., Zhao W., Zhang S., Huan W.

Materials Science Poland

2013

Vol. 31, No. 4

531--542

CS2-modified titanate nanotubes (CS2/TiO2–NTs) are fabricated by reaction of CS2 and Ti–O2Na+ species on titanate nanotubes. Pb2+ ions are coated on the modified nanotubes by ion exchange (Pb/CS2/TiO2–NTs). The products are characterized by means of nitrogen adsorption-desorption isotherms at 77 K (BET method), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD), atomic absorption spectrometry (AAS), and diffuse reflectance spectroscopy (DRS). The photocatalytic performances of the products are evaluated by monitoring their catalytic activities for degradation of methyl orange under UV light irradiation. The effects of calcination temperature and atmosphere on the photocatalytic performance are investigated. The results reveal that the photocatalytic activities of CS2/TiO2–NTs and Pb/CS2/TiO2–NTs are far higher than that of primary nanotubes, and the optimum calcination temperature is 500 °C under N2 atmosphere. It is also discovered that physically adsorbed Pb2+ ions affect the photocatalytic activity of Pb/CS2/TiO2–NTs obviously. The photocatalytic activity of washed Pb/CS2/TiO2–NTs is higher than that of the unwashed one under the same thermal treatment and reaction conditions.