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Here in this study, a novel ternary CuS/HKUST‒1/Ni(acac)2 nano photocatalyst (CSHK‒Ni) was developed through a facile modification of HKUST‒1 MOF with Ni(acac)2 metal complex and by immobilizing CuS into the metal-organic framework (MOF). The incorporation of CuS, a narrow bandgap semiconductor, is anticipated to allow easy excitation by visible-light and improve the photocatalytic potential of the formulated catalyst which is validated by the decrease in the bandgap energy from 3.10 eV of pristine MOF to 2.19 eV. Moreover, the anchoring of the metal complex improves the light harvesting behavior by increased conjugation. Photoluminescence studies provided evidence of the effective separation of the photoinduced charge-carriers, reducing the rate of recombination and enhancing the photocatalytic potential of the CSHK‒Ni nanocomposite. The engineered catalyst displayed remarkable efficiency in the degradation of nitroimidazole containing antibiotics, Tinidazole (TNZ) and Metronidazole (MTZ), via H2O2 assisted AOP achieving a maximum photocatalytic efficiency of 95.87 ± 1.64% and 97.95 ± 1.33% in just 30 min under irradiation of visible light at optimum reaction conditions. The possible degradation pathway was elucidated based on the identification of ROS and degradation intermediates via HR‒LCMS and quenching experiments. Meanwhile, the chemical oxygen demand (COD) and total organic carbon (TOC) removal were also examined, encompassing the discussing of various aspects including reaction conditions, influence of various oxidizing agents, competing species and dissolved organic substrates present in the wastewater, marking the novelty of the study. This research elucidated the role of the CSHK‒Ni nanocomposite as an interesting photocatalyst in the elimination of emerging nitroimidazole containing pharmaceutical pollutant under visible-light exposure, presenting an exciting novel avenue for a cleaner and greener environment in the days to come. [ABSTRACT FROM AUTHOR]

Biodiesel, a promising alternative to traditional petroleum fuels, is a green energy solution. Photocatalysis is a facile, novel, economic, and efficient approach to biodiesel synthesis. Metal sulfides have been used extensively for various photocatalytic applications. The present study demonstrates, for the first time, the photocatalytic production of biodiesel using a novel metal sulfide‐based heterogeneous photocatalyst under visible light irradiation. A nano zero‐valent silver doped hydroxyapatite (Ag/HAp) was synthesized using a green bio‐reductant technique and decorated with tin sulfide nanoparticles (SnS2/Ag/HAp or SAH) for photocatalytic biodiesel synthesis. The hydroxyapatite (HAp) was extracted from waste fish scales to minimize the use of chemicals and to utilize waste for useful applications. The prepared SAH photocatalyst was characterized through X‐ray diffraction, UV‐visible diffuse reflectance spectroscopy, photoluminescence spectroscopy, Fourier transform infrared analysis, energy dispersive X‐ray analysis, scanning electron microscopy, high‐resolution transmission electron microscopy and X‐ray photoelectron spectroscopy analysis. The effect of reaction parameters was optimized, and under optimum conditions of 1 wt% photocatalyst loading, and 8:1 methanol‐to‐oleic‐acid ratio, for 60 min, a high yield of 98.0 ± 0.61% could be achieved using a SAH photocatalyst. Scavenger tests indicated the simultaneous generation of photoinduced electrons and holes necessary for photocatalytic biodiesel synthesis. A mechanism for the photocatalytic esterification reaction of oleic acid is proposed. The synthesized SnS2‐based photocatalyst could be easily recoverable and reusable for five consecutive runs, which can replace traditional industrial heterogeneous catalysts in the near future. [ABSTRACT FROM AUTHOR]

Recently, many efforts have been undertaken to advance the development of sustainable biofuel production by transesterifying various oil feedstocks with methanol. In an attempt to contribute in this vein, the current research highlights the synthesis of a novel SnS 2 /Zeolite (SFAZ) composite photocatalyst for sustainable biodiesel production from soyabean oil through photocatalytic transesterification reaction under visible light irradiation. The reaction parameters influencing the biodiesel yield were optimized using Response Surface Methodology (RSM), and almost complete conversion (99.78 %) of soyabean oil into methyl esters was accomplished at a photocatalyst loading of 3 wt%, methanol-to-oil ratio of 14:1 within 60 min of visible light irradiation at 338 K. The photocatalytic transesterification reaction followed pseudo-first-order kinetics, and the activation energy needed to initiate the transesterification reaction was 28.29 kJ/mol, much lower than other catalysts. The excitation of electrons and the production of holes were required to initiate the transesterification reaction suggested by the scavenger tests, and the photocatalytic mechanism was proposed. The prepared SFAZ composite showed excellent stability and reusability of 80.46 ± 1.13 % in the fifth run. Thus, the current research provides useful insights into sustainable biodiesel production through photocatalytic transesterification reactions under visible light. [Display omitted] [ABSTRACT FROM AUTHOR]

The current research highlights the fabrication of a novel SnS 2 /CO 3 2−@Ni–Co LDH (SnS 2 /NCL) by precipitating Ni–Co LDH over hydrothermally synthesized SnS 2 nanoparticles for the enhanced degradation of thiamethoxam (THM) insecticide through the advanced oxidation process. The effect of several reaction parameters was optimized, and a maximum degradation of 98.1 ± 1.2 % with a rate constant of 0.0541 min−1 of 10 ppm THM was reached at a catalyst loading of 0.16 gL-1 using 0.3 mM of H 2 O 2 within 70 min of visible light irradiation. The effect of metal cations, inorganic anions, dissolved organic matter, organic compounds and water samples on the photodegradation performance of SnS 2 /NCL nanocomposite was also examined to evaluate the prepared photocatalyst's suitability for use in actual wastewater conditions. The metal cations blocked the active sites of the photocatalyst and reduced the degradation efficiency except for Fe2+ ions, since it is a Fenton reagent and increased the production of hydroxyl radicals. Inorganic anions are the scavengers of hydroxyl radicals and hinder photocatalytic activity. Meanwhile, lake water containing varying degrees of co-existing ions shows the lowest degradation efficiency among other water samples. The SnS 2 /NCL nanocomposite could be reused for five cycles while maintaining a photocatalytic efficiency of 83.6 ± 0.3 % in the fifth run. The prepared SnS 2 /NCL nanocomposite also showed excellent photodegradation of several other emerging organic pollutants with an efficiency of over 80 % under optimum conditions. Incorporating Ni–Co LDH with SnS 2 helped to delocalize photoinduced charges, leading to increased photocatalytic activity and a slower electron-hole recombination rate. The present research highlights the photocatalytic activity of SnS 2 /NCL photocatalysts for the photocatalytic degradation of emerging contaminants from wastewater. [Display omitted] • A novel S-scheme SnS 2 /CO 3 2−@Ni–Co LDH photocatalyst was fabricated. • Formation of S-scheme heterojunction delayed charge recombination. • Enhanced degradation of thiamethoxam insecticide under visible light. • About 98 % photodegradation of THM solution was achieved within 70 min. • Effects of inorganic ions and water matrices were investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successfully fabricated novel CO 3 2− intercalated Ni/Fe/Zn LDH encapsulated In 2 S 3. • In 2 S 3 /LDH is effective in sensing urea and photodegrading pantoprazole. • In 2 S 3 /LDH shows better sensitivity, selectivity, and reproducibility. • Photocatalytic studies exhibited 98.25 % PTZ degradation in the presence of H 2 O 2. • OH and O 2 − are the major ROSs for the photodegradation process. The Ni/Fe/Zn trimetallic LDH intercalated with carbonate ions grown over In 2 S 3 nanoparticles to form a novel In 2 S 3 /LDH nanocomposite fabricated with the combined efforts of the solvothermal and in-situ precipitation processes, as well as its enzymatic sensing and visible light-induced degradation ability, were thoroughly investigated in this study. The urease-immobilized In 2 S 3 /LDH/ITO electrode showed high-performance electrochemical sensing over a wide range of 1–240 µM with a lower limit of detection (LOD) of 0.246 µM and enhanced sensitivity of 2.29 × 10−7 A μM−1 cm−2 in phosphate buffer solution (50 mM, pH 7.5, 0.9 % NaCl) at a scan rate of 50 mV s−1. The fabricated electrode was reusable for up to 15 scans and demonstrated very high selectivity towards urea, as it showed an insignificant change in current, even in the introduction of various interferences. Furthermore, the synthesized In 2 S 3 /LDH nanocomposite demonstrated enhanced photocatalytic ability for degradation of 15 ppm of emerging sulfur-containing pollutant pantoprazole with an impressive efficiency of 98.25 ± 1.51 % in 35 min of visible light irradiation, with a high rate constant of 0.1 min−1. The H 2 O 2 -assisted AOP process showed improved COD removal of up to 87.31 ± 1.43 %, with high stability and reusability up to 7 consecutive cycles. Moreover, the as-prepared In 2 S 3 /LDH nanocomposite also showed significant degradation of other emerging pollutants with a more than 70 % degradation efficiency. As a result, this composite is a potential electrocatalyst for urea sensors in practical analysis, and it also has outstanding photodegradation of pantoprazole under visible light irradiation. [ABSTRACT FROM AUTHOR]

• Synthesis , mechanism and preparation of CNS nanocomposites of g-C 3 N 4 were discussed • Degradtion of dyes using g-C 3 N 4 and its doped form were investigated • Doped g-C 3 N 4 nanocomposites are used for effective removal of dyes from water • Non-metal doped g-C 3 N 4 has higher rate of photodegradation than metal doped g-C 3 N 4 • CNS doped semiconductors are superior photocatalyst for degradation of dyes The world is concerned about the hazardous effect of dyes that pose a threat to the ecosystem. It is therefore essential to remove these dyes from the aquatic system by using suitable methods. Among all the methods available, photodegradation using graphitic carbon nitride (g-C 3 N 4) is suitable and efficient for the removal of dyes from water and wastewater. The pure g-C 3 N 4 has low photocatalytic activity because it has a low surface area, which results in insufficient sunlight adsorption. Doping of graphitic carbon nitride was carried out to increase the photodegradation efficiency by enhancing light absorption, providing charge separation and transportation, and increasing the charge carrier lifetime. Various metals and non-metal doped g-C 3 N 4 were found to be the most effective and privileged photocatalysts for the degradation of industrial effluents in recent times. This review highlights the heterojunction-based g-C 3 N 4 and its enhanced photodegradation of the dyes. It also puts light on making the doped CNS (Carbon Nitride Sheets) nanocomposites through various techniques and on the dyes that are photodegraded using various catalysts. The photodegradation of dyes is mainly carried out under visible light radiation, as it is highly cost-effective. This heterojunction-based g-C 3 N 4 shows promising results for the photocatalytic elimination of pollutants from the aqueous phase. In this review, the working principle and mechanism of the g-C 3 N 4 photocatalysts are also discussed. Prospects and challenges faced are also discussed in this article. [Display omitted] [ABSTRACT FROM AUTHOR]