Insights into the interface effect in Pt@BiOI/ZnO ternary hybrid composite for efficient photodegradation of phenol and photogenerated charge transfer properties

Sharp-edged pencil type ZnO flowers and BiOI flakes combined with carbon nanofibers as heterostructured hybrid photocatalysts for the removal of hazardous pollutants from contaminated water

The growth of advanced micro-and nanostructures with metal oxides has consistently generated extraordinary interest in energy and environmental applications. Cutting-edge nanostructures exhibit superior reactive sites and surface areas, thus improving the performance in crucial domains. In this study, sharp-edged pencil-type ZnO flowers and BiOI flakes as pristine materials, and their composition with carbon nanofibers (CNFs) (ZnO-BiOI@CNFs) as a hetero hybrid catalyst as well as binary compositions such as ZnO-BiOI, ZnO@CNFs, and BiOI@CNFs catalysts were fabricated using a simple and convenient hydrothermal synthesis process. The composition of newly produced innovative nanostructures was examined for azo dye degradation under solar simulator exposure. Dye degradation of ∼95% was achieved by the hybrid catalyst (ZnO-BiOI@CNFs) during 120 min of irradiation, which was ∼1.8 and 2.1-times higher than pristine ZnO and BiOI nanostructures, respectively. The improved hybrid catalysts were able to degrade methyl orange (MO) and rhodamine B (RhB) dyes. Importantly, mixed dyes RhB, MO, and azo dye demonstrated 47% dye degradation using a hybrid catalyst. These mixed dye-scalable hybrid catalyst performances offer additional insights into commercialization/industrialization. The outstanding performance of the hybrid catalyst is attributed to the unidirectional electron flow with pencil-like ZnO, a catalyst with a larger absorption zone, high surface area, and reactive sites, particularly ZnO and BiOI nanostructures, and decreased recombination rate with a heterojunction interface. In addition, CNFs can operate as electron traps and sinks, providing very quick redox reactions. To produce the sophisticated nanostructures with homogeneous morphologies, this work presents new insights into energy and environmental applications.

Recent developments in photocatalysis of industrial effluents ։ A review and example of phenolic compounds degradation

Industrial expansion and increased water consumption have created water scarcity concerns. Meanwhile, conventional wastewater purification methods have failed to degrade recalcitrant pollutants efficiently. The present review paper discusses the recent advances and challenges in photocatalytic processes applied for industrial effluents treatment, with respect to phenolic compounds degradation. Key operational parameters including the catalyst loading, light intensity, initial pollutants concentration, pH, and type and concentrations of oxidants are evaluated and discussed. Compared to the other examined controlling parameters, pH has the highest effect on the photo-oxidation of contaminants by means of the photocatalyst ionization degree and surface charge. Furthermore, major phenolic compounds derived from industrial sources are comprehensively presented and the applicability of photocatalytic processes and the barriers in practical applications, including high energy demand, technical challenges, photocatalyst stability, and recyclability have been explored. The importance of energy consumption and operational costs for realistic large-scale processes are also discussed. Finally, research gaps in this area and the suggested direction for improving degradation efficiencies in industrial applications are presented. In the light of these premises, selective degradation processes in real water matrices such as untreated sewage are proposed.

In-depth study on the structures and properties of rare-earth-containing perovskite materials

Rare-earth-containing perovskite (RECP) materials have been extensively studied in various fields for their outstanding optical, electrical, magnetic and catalytic properties. In order to understand the clear relationship between structures and functions of RECP materials, the high-level and effective characterization technologies and analytic methods are absolutely necessary. Normally, diversiform measurement methods should be used simultaneously to analyze RECP materials clearly from different aspects, such as the phases, structures, morphologies, compositions, properties and performances. Therefore, this review will introduce the features and advantages of different analytic technologies and discuss their significances for the research on RECP materials. We hope that this review will provide valuable suggestions for researchers to promote the further research and development of RECP functional materials in the future.

Enhancing aqueous pollutant photodegradation via a Fermi level matched Z-scheme BiOI/Pt/g-C3N4 photocatalyst: unobstructed photogenerated charge behavior and degradation pathway exploration

Unobstructed photogenerated charge separation and transfer occurred in the photodegradation process over a Fermi level matched Z-scheme BiOI/Pt/g-C₃N₄ photocatalyst.

Synthesis, structure and optimized field emission properties of highly oriented ZnO/Pt core–shell nanorods on a Zn substrate

The current density of as-fabricated Pt15/ZnO NR emitters was about 1900 times that of the bare ZnO emitters.

Highly efficient and stable p-LaFeO3/n-ZnO heterojunction photocatalyst for phenol degradation under visible light irradiation

A series of catalysts with p-LaFeO₃/n-ZnO heterostructure were designed and prepared by hydrothermal method. The structure, surface topographies, optical properties and interfacial interactions of these photocatalysts were analyzed by XRD, SEM, TEM, PL, Uv-vis DRS, XPS, COD, TOC etc., indicating that p-n heterojunction formed at the interface between p-LaFeO₃ and n-ZnO, which enhanced the photocatalytic activity. Among them, the 20%-p-LaFeO₃/n-ZnO composite exhibits the best activity for the phenol degradation under visible light. The superior photocatalytic activity of the heterojunction photocatalyst is mainly attributed to the formation of p-n heterojunction which leads to an efficient separation of photogenerated electron-hole pairs. Besides, the 20%-p-LaFeO₃/n-ZnO heterojunction photocatalyst shows the excellent photocatalytic stability after 4 cycles. And from the free radical capture experiment, the degradation of phenol is dominated by the oxidation reaction of hydroxyl radicals and direct hole oxidation. What's more, certain intermediates were detected by HPLC and 3D-EEMs. Therefore, a photocatalytic mechanism of the 20%-p-LaFeO₃/n-ZnO p-n heterojunction catalyst for phenol degradation under visible light irradiation was proposed.