Visible light active hybrid silver decorated g-C3N4-CeO2 nanocomposite for ultrafast photocatalytic activity and toxicity evaluation.

Development of hybrid graphitic carbon nitride (GCN) nanocomposite is an emerging research area in wastewater treatment. Herein, hybrid visible light active photocatalyst of silver decorated polymeric graphitic carbon nitride and (Ag-GCN) with cerium oxide (CeO2) nanocomposite was prepared and characterized in detail. The Ag-GCN/CeO2 photocatalyst has successfully prepared by an electrostatic self-assembly approach. The synthesized Ag-GCN/CeO2 NCs photocatalysts are characterized by various physio-chemical techniques. Using the Ag-GCN/CeO2 catalyst, the excellent photodegradation efficiency of Acid yellow-36 (AY-36) and Direct yellow-12 (DY-12) dye solution were achieved 100% within 150 min sun light irradiation. The Ag-GCN/CeO2 rate constant values of 0.048 and 0.046/min has been determined for AY-36 and DR-12 dyes, respectively. The extraordinary photocatalytic activity is due to incorporation of CeO2 with Ag-GCN which play a significant role in visible light absorption, superior reactive oxygen generation (ROS) and excellent pollutant catalyst interaction. The toxicity of the photocatalytically degraded AY-36 and DR-12 dyes were measured using the soil nematode Caenorhabditis elegans, a well-established in vivo model in biology, by analyzing survival, physiological functions, intracellular ROS levels, and stress-protective gene expressions.

A Novel Nanocomposite Based on Triazine Based Covalent Organic Polymer Blended with Porous g-C3N4 for Photo Catalytic Dye Degradation of Rose Bengal and Fast Green.

Metal free visible light active photocatalysts of covalent organic polymers (COPs) and polymeric graphitic carbon nitride (g-C3N4) are interesting porous catalysts that have enormous potential for application in organic pollutant degradation. Imine condensation for COPs, and thermal condensation for g-C3N4 were used to produce the catalysts. FT-IR, Raman, NMR, UV-Vis Spectroscopy, X-ray diffraction, and scanning electron microscopy studies were used to investigate the structural, optical, and morphological features of the metal free catalysts. We have constructed COPs with a π-electron deficient (Lewis acidic) triazine core and π -electron rich (Lewis basic) naphthalene and anthraquinone rings coupled by -O and -N donors in this study. Furthermore, the prepared Bulk-g-C3N4 (B-GCN) was converted to porous g-C3N4 (P-GCN) using a chemical oxidation process, and the generated P-GCN was efficiently mixed with the COP to create a novel nanocomposite for photocatalytic application. Using the anthraquinone-based COP and P-GCN (1:1 ratio, PA-GCN) catalyst, the highest photodegradation efficiencies for the polymeric graphitic carbon nitride of 88.2% and 82.3% were achieved using the Fast green (FG) and Rose bengal (RB) dyes, respectively. The rate constant values of 0.032 and 0.024/min were determined for FG and RB degradation, respectively. Higher activity may be related to the incorporation of COP and PA-GCN, which act significantly well in higher visible light absorption, have superior reactive oxygen generation (ROS), and demonstrate an excellent pollutant-catalyst interaction.

Sunlight-driven enhanced photocatalytic activity of bandgap narrowing Sn-doped ZnO nanoparticles.

In this paper, we grab to utilize one of the trending techniques with efficient implications in wastewater treatment of organic pollutants, the photocatalytic degradation method shining out in the research field. Herein, tin (Sn)-doped zinc oxide (ZnO) nanoparticles (NPs) (Sn/ZnO) with different doping concentrations (1, 2, 3, 4, and 5 wt%) were synthesized via a simple co-precipitation assisted method and later subjected for their physico-chemical, morphological, and optical characterization. In addition, photocatalytic activity as the concerned study was investigated as to record the different doping levels of Sn/ZnO to examine the effect of doping concentration in relation with the degradation efficiency. We know that the optical bandgap of pure ZnO was 3.26 eV while it tends to increase slightly upon increasing the doping concentration. In the present investigation, methylene blue (MB) dye was used as a model pollutant to evaluate the photocatalytic activity of Sn/ZnO photocatalysts under natural sunlight. Varied doping concentrations of Sn/ZnO were compared with different characterization techniques while XRD analysis shows up 4-Sn/ZnO with sharp peak at (1 0 1) plane with smaller grain size in comparison to other Sn/ZnO samples. The morphological recognition depicts the hexagonal structure with smaller size for 4-Sn/ZnO which offers more active sites with improved photocatalytic activity, higher surface area for the transportation of pollutants. Fluorescence spectra results revealed that Sn dopant suppresses the charge carrier recombination. The lower intensity of PL indicated reduced recombination rate, which resulted in enhancing the photocatalytic activity. To investigate the possible mechanism, kinetics and reusability studies were performed. The 4% Sn-doped ZnO nanoparticle concentration showed highest photocatalytic activity when compared with other doping levels.

Visible light-driven photocatalytic dye degradation under natural sunlight using Sn-doped CdS nanoparticles.

Herein, cadmium sulfide (CdS) nanoparticles (NPs) and different concentrations (1-5 and 10 wt %) of Sn-doped CdS NPs were prepared by a chemical precipitation method using PVP as a capping agent. The synthesized NPs were characterized using various characteristic techniques such as XRD, SEM, TEM, Raman spectroscopy, UV-Vis, and photoluminescence to investigate structural, morphological, and optical properties. Optical band gap of CdS has been tuned by substitution of Sn with different concentrations. Pure CdS and Sn-doped CdS NPs were used for the photocatalytic degradation of methylene blue (MB) dye under direct sunlight irradiation. The photocatalytic activity of the Sn-doped CdS NPs is attributed to the interface actions between Sn and CdS, which significantly decreases the recombination of a photogenerated electron-hole pair. The degradation efficiencies were found to be 91.39% and 97.56% within 180 min for pure CdS and Sn-doped CdS NPs, respectively. Among the catalysts, 4% Sn-doped CdS NPs exhibit best photocatalytic degradation efficiency after 180 min of irradiation.