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This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Water pollution by toxic dyes is an environmental problem that threatens human health. A green technology to solve this problem is the use of highly efficient photocatalysts under visible/solar light to degrade these organic molecules. However, develop affordable photocatalytic particles with high luminescence performance, enhanced stability, and low degradation is still a challenge. Here, it is reported the hydrothermal synthesis of an advanced and cost-effective nanocomposite based on a ceramic, cadmium sulphide, covered by silver nanoparticles (CdS/Ag), with outstanding photocatalytic efficiency for toxic dyes degradation under ultraviolet and direct solar light. The CdS/Ag nanocomposite completely degrade the Reactive Red 120 (RR 120), Acid Black 1 (AB 1) and Direct Blue 15 (DB 15) dyes in both light irradiations. Without scavenger, about 93% of degradation was observed at 75 min, remaining a high stability (more than 90%) after fourth degradation cycles.

The present work focus on the synthesis of x% SO2−4 loaded SnO2 nanocatalyst at different percentages (x = 2.3, 4.6, 6.9, 9.2, and 11.5% w/w) for acid-catalyzed esterification. The synthesized catalysts were characterized by X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), brunauer-emmett-teller (BET), scanning electron microscopy (SEM), transmission electron microscope (TEM), temperature-programmed desorption, and thermal gravimetric analysis (TGA/DTA) techniques. Methyl levulinate is an important chemical feedstock and its production through a catalytic route has been explored in this work. All the synthesized catalysts show excellent catalytic activity towards liquid-phase esterification of levulinic acid (LA) in atmospheric pressure under non-corrosive and mild conditions. The various reaction parameters like the effect of sulfate content, reaction temperature, reaction time, molar ratio of reactants, and prepared catalyst weights are optimized to get the highest conversion and selectivity of methyl levulinates. Among them, as prepared 6.9% SO2−4 /SnO2 catalyst exhibits the highest conversation of levulinic acid (98%) and more selectivity towards methyl levulinate (100%). The catalytic stability and recyclability of the most active nanocatalysts were performed up to five successive runs and proves less variation in the catalytic activity.

Because rutile TiO2 has a potential application of its effective utilization of indoor illumination in photocatalytic environmental purification, effort has been devoted to synthesizing advanced rutile materials. Herein, we report a rare rutile nanostructure, a rutile nanobundle, synthesised via a layered titanate conversion through a simple dilute HCl treatment and drying at room temperature. This rutile nanobundle shows visible light-responsive photocatalytic activity toward the oxidative decomposition of formic acid in water significantly higher than those of a commercial rutile and anatase-based benchmark TiO2 (P25). The rutile nanobundle, moreover, can be used as a precursor in the synthesis of a mesoporous rutile embedded with a homogeneous distribution of tiny α-Fe2O3 nanoparticles. The α-Fe2O3-embedded rutile shows superior photocatalytic activity that is up to 3 times higher than a pristine rutile nanobundle and even comparable to a more costly state-of-the-art visible light-responsive photocatalyst, Au nanoparticle-supported P25.

The present work focus on the synthesis of x% SO

Novel nanostructures of h-BN and e-Fe2O3 grafted h-BN (h-BN/e-Fe2O3) have been synthesized by solvothermal method. The prepared h-BN/e-Fe2O3 nanostructures are highly reproducible. XRD analysis confirmed the phase and crystal structure of synthesized h-BN and h-BN/e-Fe2O3 nanostructures. The sheet like morphology of the nanostructured h-BN and h-BN/e-Fe2O3 are confirmed by SEM, TEM and HRTEM analyses. Moreover, the uniform distributions of e-Fe2O3 on the surface of h-BN nanosheets are confirmed by SEM and TEM images. FT-IR and Raman studies are used to identify the functional groups and structure of h-BN and h-BN/e-Fe2O3 nanostructures. The optical absorption spectra show a clear red shift in the h-BN/e-Fe2O3 nanostructure compared to pure h-BN nanosheets which shows the electronic band structure modification in BN caused by grafting of e-Fe2O3 nanoparticles onto the surface of h-BN. The chemical composition of prepared h-BN/e-Fe2O3 heterostructure is analyzed by XPS. The photo oxidative performance of pure h-BN and h-BN/e-Fe2O3 nanostructure has been studied for oxidative decomposition of formic acid under visible light irradiation. The h-BN/e-Fe2O3 nanostructure showed relatively high photo oxidative performance compared to pure h-BN.

Pure Mn3O4 and Mn3O4/rGO hybrid nanocomposites were synthesized by sol–gel based in situ reduction method. The structural properties of pure and nanocomposite materials were studied by XRD. The crystallite size of the Mn3O4 nanoparticle was reduced in the nanocomposite as observed by XRD analysis. SEM and TEM images depict the spherical morphology of pristine Mn3O4 nanoparticles and decoration of Mn3O4 nanoparticle on rGO sheets. Raman spectra confirm the formation of Mn3O4/rGO nanohybrid composites as the Ag mode of Mn3O4, D, and G bands of rGO were observed in the spectra. FTIR spectra confirm the presence of various functional groups of GO and the in situ reduction of GO into rGO. The electrochemical properties of the Mn3O4 and Mn3O4/rGO composites were investigated by cyclic voltammetry analysis using 1 M KOH as an electrolyte. The cyclic voltammetry results show the pseudocapacitance behavior of Mn3O4, whereas the hybrid nanocomposite exhibits the combined behaviors of pseudocapacitance and EDLC. The chronopotentiometry analysis demonstrated that the specific capacitance of Mn3O4/rGO nanocomposite (427 F g−1) was relatively higher than that of Mn3O4 (136 F g−1) at 1 A/g. The impact of KOH electrolyte over the specific capacitance of a electrode material was comparatively analyzed with different electrolytes. The enhancement in the specific capacitance of the nanohybrid composite was attributed due to the strong electrode–electrolyte interaction of hybrid electrode material and synergetic effect of Mn3O4 and rGO.

In this work, the Ag modified ZnS nanoparticles were synthesized via the hydrothermal method, and used for photocatalytic degradation of organic dyes. Various analytical techniques were utilized to characterize the prepared ZnS and Ag incorporated ZnS nanoparticles. The vibrational and structural properties of the prepared nanoparticles were analyzed by FT-IR and XRD, which confirm the modification of Ag in the ZnS. The broadening of the hydroxyl group after incorporation of Ag in ZnS was observed in the FT-IR spectra. The additional (111), (200), and (220) planes in XRD of Ag-ZnS belong to the silver. The increased absorbance in the entire visible region facilitates the ZnS/Ag photocatalytic performance under direct sunlight. ZnS/Ag nanoparticles showed excellent photocatalytic activity toward degradation of RR 120, DB 15, and AB 1. The ZnS/Ag catalyst efficiently degrades the RR 120 under sunlight with higher pseudo-first order kinetic k = 0.0179 min

The present work reports the investigation of monodispersed nano brass prepared by the facile electrochemical technique. The influence of reaction parameters on the size and surface morphology of the bimetallic nano alloy were investigated through high resolution scanning electron microscopy (HR-SEM) and powder X-ray diffraction (PXRD) technique. Powder XRD revealed the crystalline morphology of γ-Cu5Zn8 nano brass with an average crystallite size of 16 nm. Furthermore, TEM micrographs highlighted the crystalline texture through its lattice fringes and the average crystal size obtained is 5 nm. The chemical stoichiometry with 60:40 mol% of Zn and Cu was revealed by energy dispersive X-ray spectroscopy (EDAX) and the X-ray photoelectron spectroscopy (XPS) provided evidence for the presence of Cu and Zn through the 2p line binding energy signals. Optical responses obtained from diffuse reflectance spectroscopy (DRS) showed that the anisotropic crystals with Zn-rich composition in the low wavelength region (355 nm). The energy band gap value of 2.73 eV obtained from the optical spectrum shown it can be a good photocatalyst. The rate of photocatalytic reaction and mechanism of degradation were discussed in detail using methyl orange dye as model pollutant. Furthermore, the antimicrobial efficacy of the γ-CuZn nano alloy was examined using gram positive and gram negative bacterial strains.

The present work reports the investigation of monodispersed nano brass prepared by the facile electrochemical technique. The influence of reaction conditions on the surface morphology and size of the bimetallic nano alloy were investigated through high resolution scanning electron microscopy (HR-SEM) and powder X-ray diffraction (PXRD) technique. From the powder XRD analysis the nano alloy was identified as a [[EQUATION]] phase. The detailed investigation was carried out using transition electron microscope (TEM) for the textural features and γ-CuZn phase stoichiometry was revealed by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDAX) analyses. Optical responses were analysed using diffuse reflectance spectroscopy (DRS). The energy band gap obtained from the optical spectrum revealed it can be a good catalyst. Rate of photocatalytic reaction and mechanism of degradation were discussed in detail. Most importantly, electrodeposited γ-CuZn nano alloy reveals superior nano-catalytic activity on methyl orange dye degradation in the shorter irradiation time. Furthermore, the antimicrobial efficacy of the γ-CuZn nano alloy was examined using gram positive and gram negative bacterial strains.

Antimonene is an exfoliated 2D nanomaterial obtained from bulk antimony. It is a novel class of 2D material for energy storage applications. In the present work, antimonene was synthesized using a high-energy ball milling-sonochemical method. The structural, morphological, thermal, and electrochemical properties of antimonene were comparatively analyzed against bulk antimony. X-ray diffractometry (XRD) analysis confirms the crystal structure and 2D structure of antimonene, as a peak shift was observed. The Raman spectra show the peak shift for the Eg and A1g modes of vibration of antimony, which confirms the formation of antimonene. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) images depict the exfoliation of antimonene from bulk antimony. Thermal analysis unveiled the thermal stability of antimonene up to 400 °C with only 3% weight loss. X-ray photoelectron spectroscopy (XPS) analysis reveals the formation of antimonene, which is free from contamination. The electrochemical properties of antimony and antimonene were investigated using cyclic voltammetry (CV) and chronopotentiometric (CP) analysis, using 2 M KOH as an electrolyte. Antimonene exhibited a relatively high specific capacitance of 597 F g−1 compared to ball-milled antimony (101 F g−1) at a scan rate of 10 mV s−1. Moreover, electrochemical impedance spectroscopy (EIS) analysis revealed that antimonene has a relatively low equivalence series resistance (RESR) and low charge transfer resistance (RCT) compared to bulk antimony, which favors high electrochemical performance. The cyclic stability of antimonene was studied for 3000 cycles, and the results show high cyclic stability. The electrochemical results demonstrated that antimonene is a promising material for energy storage applications.

Efficient collection and safe disposal of toxic metals ions from aqueous solutions is critical for applications in environmental remediation. Although extensive efforts have been devoted to the synthesis of functional TiO2 materials, photocatalytic reduction (photoreduction) of aqueous metal ions into solid metals remains a challenge. We designed a TiO2 nanoparticle-decorated layered titanate (K2Ti4O9) material that retained the cation exchange ability of K2Ti4O9 but also possessed the enhanced charge separation efficiency of K2Ti4O9. Combining cation exchange with enhanced charge separation efficiency results in a heterostructured material with remarkably high activity for the photoreduction of metal ions. Initially we demonstrated how the photocatalyst can efficiently reduce aqueous Ni2+ cations, whereas the benchmark TiO2-based P25 catalyst showed little to no activity. The resulting Ni-deposited heterostructure can then be used as a catalyst for visible light-induced photocatalytic H2 evolution in water.

Photodegradation technique is also being employed with naturally available solar energy for treating toxic pollutants to protect environment. In order to achieve the effective degradation of pollutants, the photo-induced charge separation should be in suitable levels. The stability of the catalyst plays an important role in photodegradation. To achieve the above two concepts successfully, the Ag-TiO2 @Pd/C nanocomposites were fabricated by adding different percentages of Pd/C with respect to Ag-TiO2. The formation of the nanocomposites has been exclusively described by different characterization techniques. The prepared nanocomposites have been effectively tested with Reactive Red 120 (RR 120) under direct solar & UV-A light and their performances were explored. In this work, the test parameters such as photocatalyst reusability test and different dye pH have been discussed. Further, the catalyst degraded the antibiotic ofloxacin (OFL), which is being used for the treatment of a number of bacterial infections and the degradation mechanism is proposed below. GC-MS analysis was performed, based on the retention time, molecular ion peaks and intermediates were analyzed and proposed suitable degradation pathways for RR 120 and ofloxacin drug mineralization by Ag-TiO2 @Pd/C nanocomposite. In addition, the anti-microbial activity of synthesized nanocomposites was investigated against twenty pathogens such as Gram-positive Cocci (GBC) (2), Gram-positive Bacilli (GPB) (1), Gram negative Bacilli (GNB) (15) and fungal (2).