Cerium-based metal sulfide derived nanocomposite-embedded rGO as an efficient catalyst for photocatalytic application

Banana peel extract for CeO2 nanoflower synthesis: Enhancing photocatalytic activity for methyl orange dye removal and bactericidal effects

The cube architecture associated with the CeO2 nanoflowers (NFs) that generated, which had an average crystallization width of 7 nm, has been confirmed by X-ray crystallographic investigations. The method used is environmentally acceptable since it converts wasted banana peel extracts into CeO2 nanoflower. On the basis of artwork obtained from a High-Resolution Transmission Electron Microscope (HR-TEM), CeO2 nanoparticles have been observed to possess a spherical shape and an average particle diameter of 21 nm. To take the purpose of this study, green-fabricated CeO2-NFs were used to investigate the photocatalytic oxidation of methyl orange (MO) dye when exposed to sunshine. CeO2 nanofibers showed a degradation performance of 98% when compared to methyl orange dye. Evidently is a possibility that this may be caused by the presence of CeO2 nanoflowers, whereby enhance the interaction of electrons, which are holes dissolution, and adherence. Upon a single day of being exposed, the biocidal potential was tested against both gram-positive and gram-negative bacteria, including E. coli, B. cereus, and S. aureus, among others. Due to the fact that its 32 mm minimum inhibitory concentration (MIC) for B. cereus was the highest among conventional medicines. As shown by the extraordinary capabilities of WBP@CeO2 tiny particles, manipulating of flexible tiny particles to feed the purpose of achieving effective and customizable infections and dermatologist advancements is really stunning.

Boosted charge separation via Ce2S3 over dual Z-scheme ZnO-Ce2S3-MnO2 core double-shell nanocomposite for the degradation of diverse dye pollutants

Herein, core double-shell direct dual Z-scheme ZnO-Ce2S3-MnO2 nanocomposite was synthesized via a hydrothermal route along with pure ZnO, Ce2S3, MnO2, and characterized by numerous characterization tools for application in synthetic dyes degradation. The XRD, Raman, and FTIR analyses have confirmed the nanocomposite formation. TEM images exhibited the core double-shell morphology with an average particle diameter of 81 nm and stacking of ZnO, Ce2S3, and MnO2. EDX confirmed the existence of desired elements in the grown composition. The varied oxidation states, presence of defects, and fast charge transfer were also revealed from XPS, PL, and EIS. The ZnO-Ce2S3-MnO2 nanocomposite has an optical energy bandgap of 2.84 eV, capable of decomposing harmful dyes with excellent efficiency, 99.81% MB, 97.62% MO, 88.5% MR, and 58.9% EY in 40 min sunlight exposure. The effect of several operating parameters is also observed and obtained results showed the optimal catalyst dose was 20 mg, pH of 8, and dye concentration of 10 ppm. The scavenger's experiment suggests that •O2- and •OH are the main active radicals in the photodegradation reaction which is also evident in the dual Z-scheme formation. The MnO2 and ZnO layers covered the Ce2S3 (core) and dual Z-scheme formation allows rapid kinetics of redox reaction and provides plenteous channels for transfer of photo-generated charge carriers during photocatalysis. Thus, core double-shell direct dual Z-scheme photocatalysts having inorganic components could be an excellent choice for photocatalysis at the industrial level, particularly for water purification.

Nanocosmos of catalysis: a voyage through synthesis, properties, and enhanced photocatalytic degradation in nickel sulfide nanocomposites

Nanomaterials play a decisive role in environmental applications such as water purification, pollutant monitoring, and advanced oxidation-based remediation processes, particularly in semiconductor and metal sulfide-based photocatalysis. Metal sulfides are ideal for photocatalysis because of their unique optical, structural, and electronic characteristics. These properties enable the effective use of solar energy to drive various catalytic reactions with potential uses in environmental remediation with sustainable energy production. Among them, nickel sulfides (NiS) stand out for their narrow band gaps, high stability, and cost-effectiveness. This review thoroughly analyzes recent advancements in employing nickel-sulfide-based nanostructures for water decontamination. It begins by addressing environmental material needs and emphasizing the properties of nickel sulfide. To improve photocatalytic performance, controlled processes that affect the active structure, shape, composition, and size of nickel sulfide photocatalysts are examined, along with their synthesis methods. The heart of the review article is a detailed analysis of the modification of NiS through metal and non-metal doping, heterojunction, and nanocomposite formation for enhanced photocatalytic performance. The discussion also includes metal-modified nanostructures, metal oxides, and carbon-hybridized nanocomposites. This study underscores notable advancements in the degradation efficiency of NiS photocatalysts, rivaling their costly noble-metal counterparts. The analysis concludes with potential future directions for nickel sulfide-based photocatalysts in sustainable environmental remediation.

Heterogeneous Structures Consisting of Rod-like ZnO Interspersed with Ce2S3 Nanoparticles for Photo-Sensitive Supercapacitors with Enhanced Capacitive Performance

Photosensitive supercapacitors incorporate light-sensitive materials on capacitive electrodes, enabling solar energy conversion and storage in one device. In this study, heterogeneous structures of rod-shaped ZnO decorated with Ce2S3 nanoparticles on nickel foam (ZnO@Ce2S3/NF) are synthesized using a two-step hydrothermal method as photosensitive supercapacitor electrodes for capacitance enhancement under visible light. The formation of ZnO@Ce2S3 heterogeneous structures is confirmed using various structural characterization techniques. The area-specific capacitance of the ZnO@Ce2S3/NF composite electrode increased from 1738.1 to 1844.0 mF cm-2 after illumination under a current density of 5 mA cm-2, which is 2.4 and 2.8 times higher than that of ZnO and Ce2S3 electrodes under similar conditions, respectively, indicating the remarkable light-induced capacitance enhancement performance. The ZnO@Ce2S3/NF electrode also exhibits a higher photocurrent and photovoltage than the two single electrodes, demonstrating its excellent photosensitivity. The improved capacitance performance and photosensitivity under illumination are attributed to the well-constructed energy-level structure, which stimulates the flow of photogenerated electrons from the outer circuit and the involvement of photogenerated holes in the resulting surface-controlled capacitance. In addition, the assembled ZnO@Ce2S3/NF-based hybrid supercapacitor exhibits a great energy density of 145.0 mWh cm-2 under illumination. This study provides a novel strategy for the development of high-performance solar energy conversion/storage devices.

Metal sulphides and their heterojunctions for photocatalytic degradation of organic dyes-A comprehensive review

Water pollution caused by organic dyes is one of the greatest threats to the ecosystem. The removal of dyes from water has remained a challenge for scientists. Recently, metal sulphides have emerged as a potential candidate for water remediation applications. The efficient charge transportation, greater surface-active sites, and low bandgap of metal sulphides make them an excellent choice of semiconductor photocatalysts for degradation of dyes. This review summarises the potential application of metal sulphides and their heterojunctions for the photocatalytic degradation of organic dyes from wastewater. A detailed study has been presented on the synthesis, basics of photodegradation and heterojunctions and photocatalytic activity. The effect of the use of templates, doping agents, synthesis route, and various other factors affecting the photocatalytic activity of metal sulphides have been summarised in this review. The synthesis techniques, characterisation techniques, mechanism of degradation of organic dyes by Z-scheme heterojunction photocatalyst, reusability and stability of metal sulphides, and the scope of future research are also discussed. This study indicates that Scopus-based core gathered data could be used to give an objective overview of the global dye degradation research from 2008 to 2023 (15 years). All data (articles, authors, keywords, and publications) is compiled in the Scopus database. For the bibliometric study, 1962 papers relevant to dye photodegradation by sulfide-based photocatalysts were found, and this number rises yearly. A bibliometric analysis provides a 15-year evaluation of the state-of-the-art research on the impact of metal sulfide-based photocatalysts on the photodegradation of dyes.

Ultra-fast photocatalytic degradation and seed germination of band gap tunable nickel doping ceria nanoparticles

Doping transition metal ions into cerium oxide (CeO₂) results in interesting modifications to the material, including an increase in surface area, a high isoelectric point, biocompatibility, greater ionic conductivity, and catalytic activity. Herein, various concentrations (1-5%, 10% and 20%) of nickel (Ni) doped CeO₂ nanoparticle have been made by a facile chemical process. Using a variety of cutting-edge analytical techniques, the structural, optical, and photocatalytic properties of undoped and varied concentrations (1-5%, 10%, and 20%) of Ni doped CeO₂ nanoparticles have been investigated. Pure cubic fluorite structure with average crystallite sizes in the region of 12-15 nm was determined by X-ray diffraction (XRD) investigation. High resolution electron microscopy (HR-TEM), which revealed highly homogeneous hexagonal shape of the particles with average size of 15 nm, was also used to determine microstructural information. According to the optical absorption, the band gaps of Ni doped and undoped CeO₂ nanoparticles were found to be 2.96 eV and 1.95 eV, respectively. When exposed to sunlight, the narrow band gap Ni doped CeO₂ nanoparticles worked as an active visible light catalyst to remove the dyes Rose Bengal (RB) and Direct Yellow (DY). The best photodegradation efficiencies for RB and DY dyes were found about 93% and 97%, respectively, using the 5% Ni-doped CeO₂ catalyst. The apparent rate constant values of 0.039 for RB and 0.040 min^-1 were attained for DY. As well, the treated, untreated dye solution and control solutions were utilized to assess the toxicity of commercially accessible Vigna Radiata seeds. In this study exhibits percentages of length and germination increased by 30-35% when compared to dye pollutant solution. The Ni doped CeO₂ can provide a substantial alternative for current industrial waste management because of its quick photocatalytic activity and remarkable seed germination results.