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In the present study, a gadolinium oxide (Gd2O3) nanorod was successfully synthesized by simple hydrothermal method for the photocatalytic degradation of chloramphenicol (CAP) drug under UV light illumination. Interestingly, the rod like morphology was observed from the TEM images with the particle size of 20 nm. The XRD results suggested that the high crystalline nature of the Gd2O3 nanorods with the crystalline size of 13 nm. The XPS results confirmed the formation of Gd2O3 nanorods and the oxidation states of different elements were addressed. The photocatalytic degradation of CAP was performed under ultra violet light illumination on Gd2O3 nanorods surfaces. The Gd2O3 nanorods were showed enhanced efficacy compared to the standard TiO2 under UV light illumination. The photocatalytic degradation results revealed that the drug was degraded within a short span of time. 50 mg of Gd2O3 nanorods and 20 mg/mL of drug concentration were the optimized condition for the effective photocatalytic degradation. The reactive oxidative species actively involved in the photodegradation of CAP was ·OH and up to 5th recycle the Gd2O3 nanorods were possessed excellent stability. [ABSTRACT FROM AUTHOR]

In this present work, we report a novel green synthesis of MoO3 nanorods (NRs) utilizing Abutilon Indicum (A. Indicum) plant extract, containing palmitric, linoleic, linolinic acids and their derivatives which might be acting as both reducing and stabilizing agents. The synthesized catalyst has been employed to reduce toxic Cr(VI) to Cr(III) in the aqueous solution which was continuously monitored by UV-Vis absorbance spectroscopy. The structural, optical and morphological characterizations are performed using PXRD, UV-DRS, PL, FESEM, TEM, FT-IR and EDAX. The optical properties were precisely investigated by calculating the Tauc's relation. The band gap of as synthesized MoO3 was found to be 2.57 eV (483 nm) which falls under visible region, thus catalyst can be activated under solar light which could be cost effective. Biologically synthesized MoO3 NRs showed highest activity, i.e., almost 99% toward reduction of Cr(VI) under solar light. In addition to this, the photo firmness and reusability test showed that the catalyst can be reused upto five cycles without waning its activity. [ABSTRACT FROM AUTHOR]

In the present study, we report a simple approach for the fabrication of novel sulphur decorated MoO 3 nanorods (S@MoO 3 nanorods) by using simple solution process method for the very first time. The phase structural, morphology and optical properties of the as-prepared nanomaterials were comparatively characterized. The sulphur (S) nanosheets were well decorated on the surface of MoO 3 rods which was clearly observed from TEM images. The applicability of the as synthesized S@MoO 3 nanocomposite was demonstrated as superior photocatalyst for the photocatalytic reduction of toxic hexavalent chromium Cr(VI) to nontoxic trivalent chromium Cr(III) under visible light illumination. The photocatalytic reduction results suggested that the 1% of S@MoO 3 nanorods was exhibited excellent visible light photocatalytic activity efficiency compared to pure MoO 3 , S and other S@MoO 3 nanocomposites. The enhancement in the photocatalytic performance of 1% S@MoO 3 nanorods was mainly attributed to the strong absorption in visible region and low recombination or high separation efficiency for photogenerated electrons and holes. The trapping experiments reveals that O 2 ¯ radical species was strongly supported for the photocatalytic reduction of Cr(VI). The present protocols reported open up an S decorated photocatalyst might be a potential candidate for Cr(VI) removal in environmental. [ABSTRACT FROM AUTHOR]

In the present study, we report a facile and green route for the synthesis of hierarchically structured novel Cu/CdS nanorods by photo deposition method for the first time. The morphology of the newly synthesized composite was confirmed as nanorods using transmission electron microscopy (TEM) and grew well crystallinity with hexagonal phase exhibiting a crystalline size of 24 nm. The doping of copper significantly altered the bandgap from 2.43 to 2.30 eV. For the very first time, the photodegradation of different class of dyes viz azo, triphenylmethane, anionic and cationic dyes using Cu/CdS nanorods as a photocatalyst was investigated under visible light illumination. The complete degradation of the dye solution was observed within 25 min and the condition for the effective degradation was optimized. Interestingly, the present photocatalytic system was very faster than that of other CdS based photocatalytic dye degradation. The roles of Cu doping, reaction kinetics, degradation mechanism as well as catalyst stability the in photoreaction were comprehensively studied. The prevention of the electron-hole pair recombination was strongly evidenced by photoluminescence studies which showed very low emission intensity for the Cu/CdS (0.75%) compared to that of CdS and other ratios of Cu/CdS. Importantly hydroxyl radical was actively involved in the photocatalytic degradation mechanism which was strongly supported by the trapping experiments using different scavengers. The crucial role of Cu doping for the improved photocatalytic activity was mainly attributed to the superior electron transfer ability, enhanced light harvesting and boosted catalytic active sites. [ABSTRACT FROM AUTHOR]

Successful engineering of heterojunction photocatalysts remains one of the most promising routes towards fabricating materials with improved photocatalytic properties. Herein, novel Nb 2 O 5 RGO/MoO 3 ternary nanocomposites with varying MoO 3 loadings (5, 10 and 15 wt%) were carefully prepared via a two-step method involving hydrothermal synthesis and ultrasonication assisted assembly. The fabricated photocatalysts were studied using FESEM, HRTEM, XRD, UV-Vis DRS, PL, EIS and XPS to reveal their morphology, phase composition, optical response, electrochemical behaviour and chemical composition and states. As anticipated, the ternary nanostructures showed improved photocatalytic activity towards ciprofloxacin (CIP) and sulfasalazine (SSZ) compared to the single or binary nanocomposites. Specifically, the highest activity was attained at 10 wt%MoO 3 (Nb 2 O 5 -RGO/10 wt%MoO 3), which reached 85.4% and 88.2% for CIP and SSZ removal in just 60 min, respectively. This corresponds to CIP and SSZ degradation rates that were 3.6 and 2.3 times, and 4.2 and 3.4 times higher than those over Nb 2 O 5 and Nb 2 O 5 -RGO, respectively. The incorporated RGO functioned as a charge transfer bridge between Nb 2 O 5 and MoO 3 , thereby ensuring efficient migration and separation of the charge carriers, which was confirmed by EIS, and PL. Radical scavenging tests revealed that the •OH radicals were the predominant active species, and this was further confirmed using the terephthalic acid test. Finally, a plausible charge transfer pathway was proposed, and the possible SSZ degradation route was detailed based on HPLC-MS studies. This work provides a rational design of a novel material with promising environmental applications towards pharmaceutical pollution mitigation. [Display omitted] • Nb 2 O 5 -RGO/MoO 3 nanostructures prepared using hydrothermal synthesis coupled with ultrasonic synthesis. • Optimised nanocomposite shows improved activity towards CIP and SSZ. • RGO function as a charge conduction bridge between Nb 2 O 5 and MoO 3. • Nanocomposite display remarkable stability and recyclability. • Charge transfer mechanism and identification of SSZ degradation intermediates presented. [ABSTRACT FROM AUTHOR]

The design and fabrication of environmentally benign, visible light-responsive heterojunction photocatalysts remain a viable route towards sustainable exploitation of photocatalysis for water treatment. In this contribution, binary nanostructures consisting of varying ratios of In 2 S 3 and Yb 2 O 3 (In 2 S 3 /Yb 2 O 3) were obtained via a two-step method involving hydrothermal synthesis and ultrasonic treatment. The prepared materials were characterised extensively to reveal information about their morphology, optical properties, phase composition, chemical states and electrochemical properties. Subsequently, the nanocomposite photocatalysts were investigated for their dual role of photooxidation of the emerging pollutant; norfloxacin (NFX) and photoreduction of the toxic heavy metal; Cr(VI) in spiked water samples. The photocatalytic activity of the nanocomposites was found to be dependent on the photocatalyst composition (ratio of In 2 S 3 :Yb 2 O 3) and dose, contact time and initial concentration of the pollutant. Under optimised conditions, Cr(VI) reduction efficiency reached 96.4% in just 45 min of visible light irradiation and the degradation rate is 28.84 times and 3.90 times higher than that of Yb 2 O 3 and In 2 S 3 , respectively. Equally, over 95.0% NFX degradation was achieved in 50 min, under optimal conditions. The enhanced activity is credited to efficient visible light absorption, remarkable charge separation and transfer, leading to increased lifetime of the photogenerated charge carriers. Moreover, the possible degradation route for NFX was crafted based GC-MS analysis. Finally, the photostability and recyclability of the composite photocatalyst was probed and a plausible charge transfer mechanism was proposed. This work demonstrates the effectiveness of the ultrasonication method for preparing binary nanostructures and the versatility of the photocatalysts towards detoxification of both organic and inorganic pollutants in water. [Display omitted] • Hydrothermally synthesised In 2 S 3 and Yb 2 O 3 were coupled via an ultrasound assisted method. • In 2 S 3 /Yb 2 O 3 nanocomposites displayed enhanced visible light activity towards norfloxacin degradation and Cr(VI) reduction. • Composites showed improved charge separation and transfer compared to In 2 S 3 and Yb 2 O 3. • In 2 S 3 /Yb 2 O 3 nanostructures present remarkable stability and recyclability. [ABSTRACT FROM AUTHOR]