Synthesis and Characterization of 1D-MoO3 Nanorods Using Abutilon indicum Extract for the Photoreduction of Hexavalent Chromium

Novel electrospun bead-like Ag2MoO4 nanofibers coated on Ni foam for visible light-driven heterogeneous photocatalysis and high-performance supercapacitor electrodes

Novel Ag2MoO4 nanocomposite fibers were designed to enhance the photocatalytic response and supercapacitor performance of MoO3 grown via the sol-gel electrospinning technique. The Ag2MoO4 nanocomposite fibers exhibit a high specific surface area of 49.3 m2 g-1 comprising nanobeads that aggregate in the fibrous structure. The photodegradation efficiency of Ag2MoO4 was evaluated as 62% under visible light irradiation which improved to 71% with heterogeneous photocatalysis. The Ag2MoO4@Ni foam exhibited a low Rct of 19.6 Ω, and an enhanced specific capacitance of 1445 F g-1 was obtained at 1 A g-1, with 93% of its initial capacitance remaining after 5000 cycles. In addition, the Ag2MoO4//activated carbon asymmetric supercapacitor possesses an excellent energy density of 76.6 W h kg-1 at 743.2 W kg-1 and a noteworthy cycling durability of 91% after 5000 cycles. Our findings demonstrate that the electrospun Ag2MoO4@Ni foam is an important and inexpensive electrode material for supercapacitor applications and visible light-driven heterogeneous photocatalysis, drawing on the synergic effects of Ag and Mo to exhibit much better performance.

Waste to catalyst: Role of agricultural waste in water and wastewater treatment

Presently, owing to the rapid development of industrialization and urbanization activities, a huge quantity of wastewater is generated that contain toxic chemical and heavy metals, imposing higher environmental jeopardies and affecting the life of living well-being and the economy of the counties, if not treated appropriately. Subsequently, the advancement in sustainable cost-effective wastewater treatment technology has attracted more attention from policymakers, legislators, and scientific communities. Therefore, the current review intends to highlight the recent development and applications of biochars and/or green nanoparticles (NPs) produced from agricultural waste via green routes in removing the refractory pollutants from water and wastewater. This review also highlights the contemporary application and mechanism of biochar-supported advanced oxidation processes (AOPs) for the removal of organic pollutants in water and wastewater. Although, the fabrication and application of agriculture waste-derived biochar and NPs are considered a greener approach, nevertheless, before scaling up production and application, its toxicological and life-cycle challenges must be taken into account. Furthermore, future efforts should be carried out towards process engineering to enhance the performance of green catalysts to improve the economy of the process.

Enhanced Room Temperature Ammonia Gas Sensing Properties of Fe-Doped MoO3 Thin Films Fabricated Using Nebulizer Spray Pyrolysis

MoO₃ thin films are fabricated using nebulizer spray pyrolysis technique, which is doped with Fe at various concentrations of 1, 2, 3, and 4% for ammonia gas sensors application at room temperature. X-ray diffraction (XRD) study confirms the growth of the crystal by Fe doping up to 3%, nano rods shape morphology of the thin film samples observed by field emission scanning electron microscope (FESEM), reduction in bandgap is evidenced via UV-VIS spectrophotometer. Gas sensing study is performed using gas analyzing chamber attached with Keithley source meter. Since 3% Fe doped MoO₃ sample displayed nano rods over the film surface which exhibits highest sensitivity of 38,500%, in a short period of raise and decay time 54 and 6 s. Our findings confirms that the 3% Fe doped MoO₃ films suitability for ammonia gas sensing application.

Ultrasound-assisted method to improve the structure of CeO2@polyprrole core-shell nanosphere and its photocatalytic reduction of hazardous Cr6

In this work, the CeO₂@polypyrrole (CeO₂@PPy) core-shell nanosphere has been synthesized via an ultra-sonication method using bath type (WUC-D22H, Daihan Scientific, Korea) and they are utilized for the photo-reduction of hazardous Cr⁶⁺ to benign Cr³⁺. The ultrasonic frequency and power were 20 kHz and 100 W, respectively. The PPy shielded CeO₂ in aqueous solution could prevent the dissolution of CeO₂ and to improve the photocatalytic ability of CeO₂. X-ray diffraction was used to confirm the crystalline structure of as prepared CeO₂@PPy core-shell and FT-IR was used to identify the functional groups. The uniform sized core of PPy and shell of CeO₂ were observed by transition electron microscopy. The ultrasonic assisted synthesized CeO₂@PPy core-shell exhibits a narrow bandgap (UV-DRS) and good reduction efficiency with higher reusability and stability compared to pure CeO₂, PPy and mechanical mixing of CeO₂@PPy. Moreover, the synergistic effect of CeO₂ and PPy core-shell structure facilitate a higher electron transfer rate and prolong lifetime of photogenerated electron-hole pairs which can achieve good reduction rate of 98.6% within 30 min. In particular, the pH, catalyst, and Cr⁶⁺ concentration effects were optimized in photocatalytic reduction reactions. Meanwhile, this photocatalysis with fast and effective electron transfer mechanism for the Cr⁶⁺ reduction was elucidated. This method opens a new window for simple fabrication of conducting polymers-based metal oxide nanocomposite towards wastewater remediation and beyond.