ZnIn2S4/g-C3N4 Nanocomposite for Proficient Elimination of Hg (II) under Visible Light

Journal of Inorganic and Organometallic Polymers and Materials - The present work offers beneficial method for Hg (II) elimination from aqueous solution. ZnIn2S4/g-C3N4 nanocomposites were...     

Polyamide-baghouse dust nanocomposite for removal of methylene blue and metals: Characterization,kinetic, thermodynamic and regeneration

In this research, polyamide modified baghouse dust nanocomposite (PMBHD) was synthesized from steel industry waste using the interfacial polymerization technique. Adsorption capacities of the PMBHD were examined for the uptake of cadmium Cd (II), lead Pb (II), and methylene blue MB from simulated solutions. The effects of different operational factors of the adsorption, including contact time, pH, adsorbent dosage, initial concentration, and temperature, were investigated. The obtained results revealed that the equilibrium data of MB, Pb (II), and Cd (II) were best fitted to Dubinin-Radushkevich, Langmuir, and Freundlich isotherm. Maximum removal uptake was found to be 6.08, 119, and 234 mg·g^-1, whereas maximum removal efficiencies of 90%, 99.8%, and 98% were achieved for MB, Pb (II), and Cd (II). Adsorption kinetics of MB and metals well-fitted to the pseudo-second-order kinetic. The characterization results showed the presence of polymeric chain on the surface of the PMBHD. The thermodynamic study revealed that the values of the free energy ΔG for Pb (II) and Cd (II) were found to be negative, which indicates spontaneous, energetic, and favorable adsorption. While for MB removal, positive values of (ΔG) were noticed, which implies that the adsorption was unfavorable. The proposed mechanism for the adsorption of MB and metals on the PMBHD showed that the dominating mechanism is physisorption. The adsorption/desorption results verified the high reusability of the PMBHD for adsorption of MB and metals.     

La-doped NaTaO3 nanoparticles: Sol-gel synthesis and synergistic effect of CdO decoration toward efficient visible-light degradation of ciprofloxacin in water

The expanded use and disposal of antibiotics in water has led to health and environmental problems. However, photocatalysis is an efficient way to make progress toward the safe destruction of this emergent waste. Here, we present the photocatalytic degradation of ciprofloxacin (CP), an emerging antibiotic probe, over sol-gel synthesized La-doped NaTaO₃ (LNTO) nanoparticles. We also studied the synergistic influence of adding a low amount (1.0–4.0 wt %) of CdO nanocrystals to the LNTO to enhance the photocatalytic performance under visible light. The introduction of CdO at only 3.0–4.0 wt% assisted the visible light response of the LNTO by reducing the bandgap energy (E_g) from 4.1 to approximately 2.6 eV and maintaining the high surface area of the mesostructured surface at 188 m² g^?1. Additionally, the 3% CdO-loaded LNTO demonstrated complete photodegradation of CP within 90 min and a 732-fold increase in the degradation rate compared to that of pristine LNTO. The obtained CdO-modified LNTO could also be reused five times with negligible reduction in performance. The results reflect the significant contribution of CdO to the promotion of photoinduced charge separation. This study demonstrates the use of perovskite-based photocatalyst modification with simple oxides to promote sustainable visible-light degradation of such antibiotic waste in water.     

Facile Fabrication of Pt-Doped Mesoporous ZnS as High Efficiency for Photocatalytic CO2 Conversion

Developing high efficiency, environmentally friendly, and low-cost mesoporous Pt/ZnS photocatalyst for CO₂ conversion to CH₃OH is significant for clean energy conversion. Herein, we described a facile synthesis of mesoporous ZnS framework decorated Pt NPs as high efficiency for CO₂ conversion through visible light illumination. The results indicated that Pt/ZnS nanocomposites showed that the structural and crystallinity integrity of polyhedral heterojunction obviously maintain after incorporating Pt NPs, and they are well-distributed on the ZnS surface with particles size about 3–5 nm. The optimized photocatalyst 1.5% Pt/ZnS nanocomposite could prominently exhibit a high photocatalytic efficiency compared to undoped ZnS. Remarkably, the yield of CH₃OH of 400 µmolg^??1 in 9 h over 1.5% Pt/ZnS nanocomposite indicated a significantly promoted CH₃OH formation, nearly 22-fold greater than that of the undoped ZnS NPs, which substantially verified the great promoting potential for conversion of clean energy. The CH₃OH formation rate over mesoporous 1.5% Pt/ZnS nanocomposite (44.5 µmolg^?1 h^?1) is larger 24 times than that of undoped ZnS NPs (1.86 µmolg^?1 h^?1). The recycled Pt/ZnS photocatalyst does not alter the CH₃OH formation remarkably after five repeating cycles with excellent durability. Electrochemical impedance spectroscopy, photocurrent response, and photoluminescence analyses were investigated to support our results and suggested mechanism for enhancement of CO₂ conversion to CH₃OH.