Excellent photo- and sono- catalytic BiOF/Bi₂O₃ heterojunction nanoflakes synthesized via pH-dependent and ionic liquid assisted solvothermal method

Abstract Herein, a series of BiOF/Bi₂O₃ heterojunction nanoflakes were designed. The XRD and TEM confirm that the phase structure and morphology of BiOF/Bi₂O₃ were affected by the pH value of the precursors. The catalytic activities were investigated in different catalytic ways including photocatalytic activity under ultraviolet light, photocatalytic activity under visible light and sonocatalytic activity under ultrasonic irradiation. It concluded that the catalytic performances of BiOF/Bi₂O₃ are substantially affected by laboratorial pH values. The BiOF/Bi₂O₃ prepared at lower pH values exhibited enhanced catalytic activity attributed to the favorable morphology and band gap energy. Meanwhile, it shows excellent sonocatalytic performances due to the synergistic effect of BiOF/Bi₂O₃ and H₂O₂ in sonocatalytic process. The sonodegradation efficiencies of rhodamine B reaches 95.28 % in the presence of three drops of H₂O₂ within 10 min of ultrasonic irradiation. The catalytic mechanism reveals that ·OH as the dominant active specie plays a key role in degrading the dyes both under UV light illumination and ultrasonic irradiation

Synthesis of CdS-loaded (CuC₁₀H₂₆N₆Cl₂O₈)₃(PW₁₂O₄₀)₂ for enhanced photocatalytic degradation of tetracycline under simulated solar light irradiation

Abstract Largely discharged and excreted medical pollutants pose huge threats to ecosystems. However, typical photocatalysts, such as the Keggin-typed H₃PW₁₂O₄₀, can hardly degrade these hazards under visible-light due to their broad bandgap and catalytic disability. In this work, the visible light harvesting was enabled by combining macrocyclic coordination compound CuC₁₀H₂₆N₆Cl₂O₈ with H₃PW₁₂O₄₀, and the resulting CuPW was loaded with CdS to reach robust catalytic ability to totally detoxify medicines. We prepared the CuPW–CdS composites through a facile precipitation method, and it showed excellent photocatalytic degradation for degrading tetracycline under visible-light irradiation. The (CuC₁₀H₂₆N₆Cl₂O₈)₃(PW₁₂O₄₀)₂ with 10 wt% load of CdS shows the highest performance and is ∼6 times more efficient than the pure CuPW counterpart. The heterojunctional CuPW–CdS composites promote the separation of electrons and holes, and consequentially enhance photocatalytic activity. Thanks to migration of electrons from CdS to CuPW, the photocorrosion of CdS is prohibited, resulting in a high chemical stability during photocatalysis. In this work we design a new route to the multi-structural composite photocatalysts for practical applications in medical pollutant decontamination

A facile synthesis of heterojunctional BiVO₄/Bi₅O₇I with enhanced photocatalytic activity for organic dyes degradation

Abstract Photocatalysis technology has risen to effectively degrade the hardly-degraded organic pollutants in recent years and the photocatalysts play an important role in striding the obstacles of the visible light response. Herein, a high-efficiency BiVO₄/Bi₅O₇I heterojunctional photocatalysts have been purposefully designed by controlling the reactant ratios and ultrasonic time of reaction at room temperature. Photocatalytic experimentals confirm that the prepared optimal BiVO₄/Bi₅O₇I composites displayed enhanced photocatalytic ability to degrade rhodamine B and quinoline blue under visible light irradiation. Furthermore, the photocatalysts exhibits high photostability and reusability proved by four consecutive cycling experiments. A possible mechanism of p–n heterojunctional BiVO₄/Bi₅O₇I composites enhanced the photocatalytic performance was discussed in detail on the basis of the reactive species trapping experiments in photocatalytic degradation process

A facile morphology-controllable synthetic route to monodisperse K₃PMo₁₂O₄₀▪nH₂O crystals

Abstract Synthesis is the base of experimental chemistry. Herein, monodisperse K₃PMo₁₂O₄₀▪nH₂O polyoxometalates with different morphologies have been reached by tuning synthetic conditions of the K/POM ratio, stirring speed and time, and reaction temperatures. Among these factors, the K/POM ratio is identified most critical in morphological controls of the K₃PMo₁₂O₄₀▪nH₂O particles, altering them from cubes to spheres. Additionally, morphological transformations were identified through a self assembly and Ostwald ripening process, setting a generic synthetic strategy for the POM systems. Such synthetic strategies have substantial applications in catalytic or surface demanding fields requiring POM materials with controlled morphology

Iodine doped Z-scheme Bi₂O₂CO₃/Bi₂WO₆ photocatalysts:facile synthesis, efficient visible light photocatalysis, and photocatalytic mechanism

Abstract The Bi-based hierarchical multi-component photocatalytic system is an important player in energy and environmental catalysis due to its full-spectrum light absorption and stable separation of photo-generated charges. In this study, a novel family of iodine doped Bi₂O₂CO₃/Bi₂WO₆ heterojunctions was successfully developed by a facile ionic liquid assisted solvothermal method. A visible light photocatalytic H₂ production rate of 664.5 μmol g−1 h−1 (0.3I-Bi₂O₂CO₃/Bi₂WO₆ with 3% Pt) has been durably obtained, much higher than those of pristine and undoped counterparts. The photocatalysts are also capable for persistent pollutant and dye degradation. Through electrochemical and spectroscopic tests and density functional theory calculation, the enhanced photocatalytic activity is attributed to formation of the Z-scheme photocatalyst. Therein, the lowered and indirect bandgap and heterojunctional band alignment spontaneously benefit visible light harvesting, electron-hole pair separation, and proton reduction. Besides a facile synthesis for effective photocatalysis, the Z-scheme mechanism is hoped to facilitate the design and realization of similar systems for photocatalytic H₂ evolution and organic hazards decontamination