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A photostable sunlight-responsive mesoporous Cu +1 /Cu 0 –TiO 2 (Cu-mpTiO 2 ) photocatalyst has been fabricated for the H 2 production from water. Structural analysis revealed the anatase polymorph of TiO 2 with mesoporous characteristics and an average particle size of ∼32 nm. Mesoporous TiO 2 was observed to possess high surface area (188 m 2 g −1 ) and pore size (0.32 nm). HRTEM studies suggested the deposition of Cu in Cu 0 and Cu +1 oxidation states with three distinct lattice fringes of 0.21, 0.25, and 0.35 nm for Cu, Cu 2 O, and TiO 2 respectively. Cu-mpTiO 2 produced 1000 μmol of H 2 (AQE = 11.39%) under sunlight irradiation, which is severalfold more than obtained with Cu impregnated on commercial Cu–TiO 2 (P25). The photostability of the Cu–mpTiO 2 increased after recycling because the excess Cu +1 (binding energy = 533.5 eV) is reduced to Cu 0 (533.3 eV) and the excess holes in the valance band of Cu 2 O oxidize Cu 0 to Cu +1 . [ABSTRACT FROM AUTHOR]

Elimination of pharmaceutical drugs from wastewater through photocatalysis is considered an effective and environment-friendly approach to prevent their introduction into the aquatic environment. We constructed ternary Ag deposited g-C 3 N 4 loaded Co Al layered double hydroxide (LDH) composites through multistep synthesis for wastewater remediation of the pharmaceutical industry. We explored the role of g-C 3 N 4 (CN) and Ag NPs in Ag@CN-LDH heterostructure for improving the photocatalytic performance of LDH. This study revealed that the photoactivity of the ternary composite got significantly affected by the CN and Ag loadings. The visible light-driven ternary composite with 10 wt% of CN and 1 wt% of Ag loadings over LDH exhibited the maximum 97% degradation of commercial ciprofloxacin within 90 min, which was highly superior to that noticed for bare LDH. The improved photocatalytic proficiency was credited to the expanded surface region, quick charge move at the CN-LDH interface, and the Surface Plasmon resonance and electron-accepting capability of Ag NPs. The ternary composite was highly stable and recyclable up to five cycles with less than a 3% fall in degradation efficiency. The LC-MS analysis was performed to determine the intermediates and final products. Three degradation pathways were proposed including the cleavage of the piperazine ring and the decarboxylation of the quinoline ring. A possible mechanism for efficient charge transfer and photocatalytic degradation was proposed based on the band edge positions calculated from valence band XPS spectra, photoluminescence analysis, and scavenging experiments. [Display omitted] • Ternary composite of Co Al LDH, g-C 3 N 4 and Ag was constructed. • Influence of g-C 3 N 4 and Ag loading onto LDH properties was explored. • The composite with 10 wt% CN and 1 wt% Ag over LDH degraded 97% of ciprofloxacin. • Strong interactions between LDH, CN, and Ag boosted the photoactivity. • Mechanism and possible pathways of ciprofloxacin degradation were proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu, Ag, and Au NPs were loaded onto Mg-Al LDH with varying sizes Au > Ag > Cu. • Influence of plasmonic metals over physicochemical properties was investigated. • Au loaded LDH composites exhibited the highest degradation of tetracycline. • Schottky junction and the SPR effect were responsible for improved photoactivity. This work focused on the enhancement of the photocatalytic activity of solvothermal synthesized Mg 0.667 Al 0.333 (OH) 2 (CO 3) 0.167 (H 2 O) 0.5 layered double hydroxide (LDH) by plasmonic metal (Cu, Ag, and Au) photodeposition (1-3 wt%). HRTEM analysis confirmed the successful loading of plasmonic nanoparticles with varying sizes (Au (∼4–25 nm) > Ag (∼3–12 nm) > Cu (∼2–7 nm)) on the surface of LDH. The effect of different plasmonic metals and their size on the surface structural, optical, electrokinetic, and photocatalytic properties of LDH was investigated. The prepared catalysts were evaluated for the degradation of tetracycline under LED irradiation for 140 min and the photoactivity trend followed the order: pristine LDH < Cu@LDH < Ag@LDH < Au@LDH. The LC-MS studies revealed that the degradation occurred by the attack of various reactive species (O 2 .-, h+, OḢ) via four paths mainly including hydroxylation, functional group cleavage, and ring-opening reaction. A possible mechanism was proposed for the appreciable enhancement in performance caused by the formation of Schottky barriers and surface plasmon resonance of plasmonic nanoparticles. The results of total organic carbon (TOC) indicated the acceptable mineralization of about 84 %. Less than a 10 % fall in degradation efficiency was observed within four recycle runs. [ABSTRACT FROM AUTHOR]

The co-catalytic activity of 1 wt% coinage (Au, Ag and Cu) metals and platinum group (Pt, Pd and Rh) metals deposited P25 and rutile TiO 2 (R-TiO 2 ) have been relatively investigated for the optical absorption, emission, surface structural morphology and photocatalytic activity for the selective reduction of m -dinitrobenzene under UV light irradiation. An average particle size ∼122 nm of R-TiO 2 is increased after calcinations of P25-TiO 2 (25–30 nm) at 800 °C and Au and Pt deposits of size ∼4.0–6.5 nm were found to be uniformly distributed over TiO 2 surface. Although the optical band gap does not alter much, but intense photoluminescence having several characteristic bands between 400 and 550 nm are significantly quenched depending on the nature of metal loading. Photoirradiation (125 W Hg arc, 10.4 mW cm −2 ) of bare P25-TiO 2 suspended in isopropanol (50 vol%) containing m -dinitrobenzene selectively produces 100% m -phenylenediamine, while metal deposited P25-TiO 2 produces m -nitroaniline as a major product after 4 h of UV light irradiation. However, bare R-TiO 2 produces 100% m -nitroaniline and metal loading does not alter the selectivity except the decrease in reduction efficiency of R-TiO 2 . The decrease in active Ti 3+ sites available on the surface after metal loading might be responsible for the decrease in photocatalytic activity. [ABSTRACT FROM AUTHOR]

Mesoporous silica SBA-15 having pore size (∼8 nm) was prepared using Pluronic P123 triblock copolymer followed by its surface modification with 2 wt.% of 3-aminopropyltriethoxysilane (APTES). The Au (1–10 wt.%) impregnation led to the formation of homogeneously dispersed Au nanospheres of size 5–6 nm, and nanorods of length 90–180 nm (and width 6–9 nm) throughout the APTES-modified SBA-15 without any distortion in the long range ordering of mesochannels. It was found that increasing amount (1–10 wt.%) of Au loading followed by calcination at 350 °C resulted in change of spherical morphology to rod like Au nanostructures beyond 5 wt.% loading. The surface area (664 m 2 /g) and pore volume (1.33 cm 3 /g) of bare SBA-15 were significantly reduced to 292 m 2 /g and 0.6031 cm 3 /g for Au nanosphere, and 457 m 2 /g and 0.7677 cm 3 /g for Au nanorod dispersed SBA-15, respectively, due to partial filling of mesopores. The catalytic activity of APTES-modified SBA-15 for the reduction of m - and p -dinitrobenzene is abruptly enhanced, after optimum amount (4–10 wt.%) of Au dispersion following a pseudo first order kinetic law that exhibited the best yield and 89% selectivity for m -phenylenediamine and 81% for p -nitroaniline formation, respectively. [ABSTRACT FROM AUTHOR]

This work demonstrates the preparation of monoclinic crystalline CuO nanospheres (5–10 nm), nanorods ( L × W = 100–140 nm × 30–40 nm) and nanowires (200–210 nm × 2–5 nm) for the study of thermal conductivities when dispersed in de-ionized water and ethylene glycol (0.005–0.1 vol%). It has been observed that CuO nanorods and nanowires having surface area 53 and 61 m 2 g −1 , respectively, always displayed higher thermal conductivity than CuO nanospheres possessing lower surface area (41 m 2 g −1 ), which attributed to the differences in their per-particle surface area, percentage of surface exposed atoms, anisotropic lengthy shape, large phonon-mean-free paths. The experimental results revealed higher thermal conductivities than obtained from theoretical models due to particle shape effect as expected from Hamilton–Crosser equation. It has also been found that density is directly proportionally to thermal conductivity and increases with the increase in volume fraction. The decrease in aggregated particle size (130–104 nm) and an increase in zeta potential value (−32 to −37 mV) of CuO nanospheres causes more stability of CuO dispersion with 3–6 h of sonication. [ABSTRACT FROM AUTHOR]

Highlights: [•] Superior photocatalytic activity of sodium titanate nanotube to P25-TiO2. [•] Electro-kinetic properties vary with synthesis condition of TiO2nanostructures. [•] Ag and Cu deposition did not significantly alter the electro-kinetic parameters. [•] Sodium content has no detrimental effect on the photoactivity of titanate nanotube. [ABSTRACT FROM AUTHOR]

The capped ZnS NPs (ZnSM1 and ZnSM2) found to be highly photoactive towards crystal violet (CV) dye. Nearly 93% and 88% degradation of CV was observed under UV and sunlight whereas very efficiency was shown by uncapped (ZnSUC) and standard ZnS nanostructures. [Display omitted] • Different capping agents influenced morphology of ZnS NPs. • Successful passivation of functional groups over ZnS surface. • Surface defects made ZnSM1 and ZnSM2 quite photo-responsive under sunlight. • Efficient photostability determined by recyclability of ZnSM1 and ZnSM2. • 88% of CV degradation was observed using ZnSM1 under sunlight. Photo-responsive ZnS nanostructures (ZnSM1 and ZnSM2) were synthesized using 3-mercaptopropionic acid (MPA) and polyvinylpyrrolidone (PVP) capping agents respectively via reflux method. Capped photocatalysts hold unique optical properties such as absorption in visible region, multi band gap values and surface defects. Interestingly, structural analysis revealed that nanorods and nanospheres were formed with MPA and PVP whereas randomly arranged particles were formed without using any capping agent (ZnSUC). The successful passivation of COOH (1549 cm−1 and 1357 cm−1) in case of ZnSM1 whereas CH 2 (1284 cm−1) and C N stretching (1429 cm−1) for ZnSM2 was determined by FT-IR studies. Owing to effective charge separation, 1D structure, suitable band gap energies and higher surface area (252 m2g−1), ZnSM1 exhibited enhanced photocatalytic activity towards crystal violet degradation (CV, 93%) under UV light which was about two folds higher than standard ZnS. Under sunlight, uncapped ZnS nanoparticles (ZnSUC and std. ZnS) showed minor activity in comparison to capped ZnSM1 (88%) and ZnSM2 (77%). Moreover, 83% degradation of 2-nitrophenol (NP) was obtained using ZnSM1 without using any other reducing agent under solar irradiations. Thus, present work provides more insights to understand the outstanding activity of ZnS nanomaterials towards organic pollutants beyond UV region without metal deposition. [ABSTRACT FROM AUTHOR]

Nowadays, pharmaceutical waste, Naproxen (NPX) as well as the dye fuchsin blue (FB) become hazardous pollutant due to their toxic behavior. Because of toxicity, the efficient removal of them from water has become one of the most vital challenge. Yet, due to high cost, low degradation efficiency, of the known catalyst restrict their real life applications. In this perspective, metal ions impregnated (Ni2+ and Cu2+) Bi 2 O 3 heterostructures have been investigated as a potential material for photocatalytic degradation of NPX and FB. These materials are synthesized by simple wet-impregnation method and thoroughly characterized by various methods such as XRD, DLS, SEM, EDS, HRTEM, XPS, etc. The diffraction patterns confirm formation of phase pure α-Bi 2 O 3 nanoparticles. The zeta potential (−25 mV) of Bi2O3 nanoparicles confirms presence of negatively charges oxide groups in its surface that can act as anchors for divalent anions. The impregnated hybrids shows considerably smaller zeta potential values (−15 and −17 mV for Ni2+-Bi 2 O 3 and Cu2+-Bi 2 O 3 respectively). The XPS studies reveal presence of surface bound divalent metal ions. The adsorption edge of Ni2+-Bi 2 O 3 and Cu2+-Bi 2 O 3 nanostructures were shifted slightly towards lower frequency. The photoluminescence spectrum impregnated materials shows significant quenching compare to pristine Bi 2 O 3. suggesting lesser degree electron-hole recombination upon metal loading. Due to the photocatalytic degradation efficiencies of both Ni2+-Bi 2 O 3 (87% for FB and 79% for NPX) and Cu2+-Bi 2 O 3 (73% for FB and 70% for NPX) heterostructures are significantly higher compare to the pristine one (43% for FB and 40% for NPX). The photo-degradation process obeys the pseudo first order kinetics. Due to simpler synthesis and enhanced activity metal ion loaded Bi 2 O 3 photocatalysts can be potential photo-catalysts for removing NPX and FB from wastewater. Effect of varying wt% of metal ion impregnated Bi 2 O 3 on surface charge and photocatalytic properties of Fuchsin blue and Naproxen under visible light illumination. Image 1 • Improved optical and photocatalytic properties of Ni2+ and Cu2+ loaded Bi 2 O 3 catalysts. • Greater quenching of emission peak intensities of photocatalysts. • Superior degradations of naproxen and fuchsin blue under visible light irradiations. [ABSTRACT FROM AUTHOR]

This report signifies the synthesis of ZnO nanorods, cotton ball like structures, nanospheres and their Cu loaded counterparts for effective photocatalytic degradation of methyl parathion pesticide under UV light. Pesticides accumulation in ecosystem becomes major problem which affects health. Zinc oxide is a promising photocatalyst for degradation of pesticides and dyes because of its higher stability, low cost and non-toxic nature. Herein, the synthesized catalysts were characterised by diffused reflectance spectroscopy, X-ray diffraction, scanning electron microscopy techniques and transmission electron microscopy. ZnO nanorods (ZNR) proved to be better catalyst as compare to other synthesized nanostructures because of its elongated morphology. ZNR were nearly 1.4 times more efficient than ZnO cotton ball like structures. Moreover, photocatalytic activity was also enhanced by Cu loading due to low recombination rate of excitons. Cu loaded ZNR were found to degrade whole compound up to 99% in just 80 min whereas bare ZNR took 3 h under similar conditions. Thus, efficiency of Cu-ZNR had been increased nearly 6 folds as that of bare ZNR. This work demonstrates the effect of different morphologies and their Cu deposited counterparts for enhanced photocatalytic degradation of methyl parathion (MP) pesticide. Image 1 • Morphology of the catalysts influenced reaction efficiency. • Cu loading has improved methyl parathion (MP) degradation rates. • Cu deposited ZnO nanorods like particles degraded MP upto 99% in just 80 min. [ABSTRACT FROM AUTHOR]

This study demonstrates the synthesis of TiO 2 nanosheets (TNST) exhibiting high percentage (54%) of exposed (001) facets and decorated with co-deposited gold and platinum nanoparticles (NPs). The as synthesized as well as modified sheets are then investigated for the photo-reduction of water under sunlight irradiation using different alcohols as hole-scavengers. Structural and morphological studies manifest the formation of well-defined sheet structure of TiO 2 with average dimensions of 55 nm × 46 nm. The measured d spacing of 0.34 nm and 0.23 nm corresponds to (101) and (001) facets of anatase TiO 2 . The presence of Au and Pt was confirmed by electron diffraction and X-ray photoelectron spectroscopy. TiO 2 nanosheets (TNST's) with 0.4 and 0.75 wt % of Au and Pt (Au 0.4 /Pt 0.75 -TNSTs), respectively were found to exhibit higher efficiency. Furthermore, photo-electrochemical (PEC) water splitting studies revealed the increase in photocurrent from 2 mA at 0.5 V to 4.5 mA at 0.65 V for Au 0.4 /Pt 0.75 -TNST photoelectrodes, which otherwise was 0.15 mA for the bare TNST photoelectrodes at the same potential. The observed PEC performance was well supported by impedance analysis, wherein Au 0.4 /Pt 0.75 -TNSTs (338 Ω) are found to exhibit lower resistance in comparison to bare TNST (737 Ω), which could be due to brilliant photo conductance and interfacial charge transfer properties of Au 0.4 /Pt 0.75 -TNSTs. Photocatalytically the Au 0.4 /Pt 0.75 -TNST produced ∼143 μmol h 1 of H 2 gas under direct sunlight irradiation, which is found equivalent to 16.1% apparent quantum efficiency. [ABSTRACT FROM AUTHOR]

Lengthy TiO 2 nanostructures exhibiting improved physicochemical properties have been recently investigated for many useful applications. In this context, elongated TiO 2 nanowires (TNW) of length 1.9–8 µm; diameter 80–270 nm are prepared and 1 wt% Au was photodeposited onto TNW for enhanced photo-degradation of propiconazole fungicide under UV/visible light irradiation. The phase composition of TNW (anatase = 72%, rutile = 28%) was almost similar to commercially available P25 TiO 2 (anatase = 70%, rutile = 30%). TEM analysis reveals uniform dispersion of spherical Au nanoparticles (3–5 nm) deposits over entire TNW surface. The specific surface area 148 m 2 g −1 of TNW is notably higher than 59 m 2 g −1 of P25 TiO 2 which is reduced slightly to 136 m 2 g −1 after Au loading. TNW exhibited increased (45–64 µs) relaxation time of photoexcited e − /h + pairs as compared to P25 TiO 2 due to its elongated structure and after Au loading further improves the charge separation efficiency (79 µs). The complete photodecomposition of propiconazole to CO 2 by bare and Au-loaded TNW under light irradiation through formation of various intermediate products was monitored through HPLC, GC and GC–MS analysis. It revealed that Au-loaded TNW always exhibited 3.5–40 times higher photocatalytic activity than mostly used P25 TiO 2 because of more anatase phase, larger specific surface area and a higher lifetime of excited charge species where Au loading enhanced the visible light absorption capacity due to surface plasmon interaction. [ABSTRACT FROM AUTHOR]

The present work outlines the importance of biosynthesized selenium nanoparticles (SeNPs) as co-catalyst for the enhanced photocatalytic activity of as-prepared ZnS photocatalyst for degradation of methyl orange (MO) dye under UV light irradiation. SeNPs of different wt% were impregnated onto ZnS by calcination at 200 °C to make Se-ZnS nanocomposites (Se-ZnSNCs) and characterized by UV–Vis spectroscopy, DLS, XRD, SEM-EDX, TEM and BET surface area analysis. The specific surface area notably increased from 54 m 2 g −1 (ZnS) to 75 m 2 g −1 with different wt% of Se loading. The band edge absorption at 330 nm (3.77 eV) of bare ZnS significantly red-shifted to 357 nm (3.30 eV), after 1 wt% Se loading (3.30 eV). 1 wt% Se-ZnSNCs exhibited the highest degradation efficiency (95%) of MO as compared to bare ZnS (55%) under 160 min UV light irradiation. The reaction followed pseudo first-order kinetics with an apparent rate constant k = 8.42 × 10 −3 min −1 where CO 2 evolution gradually increased depending on the extent of MO degradation by Se-ZnSNCs under different time period of UV light irradiation. [ABSTRACT FROM AUTHOR]

SBA-15 modified with APTMS (3-aminopropyl trimethoxysilane) having pore diameter (∼8 nm) has been synthesized and impregnated with 1–10 wt.% Cu using Cu(NO 3 ) 2 as a metal source followed by calcination at 350 °C. As-prepared CuO/ap-SBA-15 powder showed changes in the color from white for bare SBA-15 to light green due to formation of anisotropic CuO nanoparticles that exhibited a characteristic plasmon absorption band at 359 and 747 nm. TEM studies showed a change in the morphology of CuO NPs as a function of increased Cu loading. Moreover, well dispersed CuO nanospheres (∼5–6 nm) and nanorods (aspect ratio ∼11–20 nm) having monoclinic crystal phase were observed within the mesoporous channels of SBA-15. Elemental mapping studies confirmed uniform distribution of CuO nanoparticles on the surface of SBA-15. An increase in surface area was also observed from 694 m 2 g −1 for SBA-15 to 762 m 2 g −1 for 10 wt.% Cu loading probably due to the deposition of excess of CuO nanoparticles on the outer siliceous surface. The catalytic activity also increased with Cu loading and 10 wt.% CuO/ap-SBA-15 catalyst displayed the highest catalytic activity for the reduction of m -chloronitrobenzene and m -nitrotoluene with 83% and 100% selectivity for m -chloroaniline and m -aminotoluene respectively. [ABSTRACT FROM AUTHOR]

The activity of different wt% Ag co-catalyst over TiO 2 surface under varying UV illuminations (30, 60 and 90 min) for the photodegradation of salicylic acid has been studied. A considerable red shift in the plasmon band was observed with a significant color change (white to light brown) with increased photodeposition time (30–90 min) of Ag over TiO 2. Further, the elemental mapping confirms a continuous increase in the wt% of Ag with increased deposition time from 30 min (0.21 wt%) to 90 min (1.69 wt%). These 1, 3 and 5 wt% Ag deposited nanocatalysts prepared at 90 min duration showed higher activity for the photodegradation of salicylic acid under UV light irradiation compared to their counter parts of 30 and 60 min. The higher rate constant (k = 2.73 × 10−2 min−1) value shown by (5 wt% Ag) 90 @TiO 2 is appreciably higher compared to (1 wt% Ag) 90 @TiO 2 (k = 2.29 × 10−2 min−1) and (3 wt% Ag) 90 @TiO 2 (k = 2.33 × 10−2 min−1) photocatalyst and followed pseudo first order kinetics. The maximum activity of (5 wt% Ag) 90 @TiO 2 catalyst has been credited to higher size, number and distribution of Ag co-catalyst nanoparticles over TiO 2 surface which greatly vary with change in amount and photodeposition time of Ag nanoparticles. Image 1 • Impact of Ag co-catalyst size/distribution on the Ag@TiO 2 photocatalytic properties. • Optical absorption of Ag plasmon band significantly vary with Ag deposition time. • Hydrodynamic size of Ag@TiO 2 varied with the amount of Ag and UV irradiation time. • Degradation of salicylic acid notably depends on deposition time and amount of Ag. • 5 wt% Ag@TiO 2 exhibited highest rate for salicylic acid degradation under UV light. [ABSTRACT FROM AUTHOR]

The problem of antibiotic-induced water pollution has attracted public attention in the modern world. Antibiotics have the capacity to cause massive hazardous damage at very low dosages due to their long-lasting biological stability. To address this issue, a new highly stable, reusable, greener, nontoxic, easily accessible composite material (CuAl-LDH/CL) consisting of Cellulose (CL) modified CuAl-layered double hydroxide was successfully synthesized. The fabricated photocatalyst was extensively studied for its optical, structural, and morphological properties using XRD, Raman, HR-TEM, FE-SEM, FTIR, BET, and UV-visible DRS methods. The CuAl-LDH/CL composite possesses a synergistic effect of adsorption and photocatalysis in the elimination of doxycycline (DOX) antibiotics from wastewater systems. The detailed thermodynamic information (ΔG = -24.27 KJ mol -1 ) including adsorption maximum capacity q max (150.16 mg/g), adsorption equilibrium constant (k = 0.18 × 10 5  M -1 ), and adsorption efficiency (40.36 %) along with degradation rate constant (k = 0.0116 min -1 ) and degradation efficiency (96.2 %) was evaluated. The pathways of DOX degradation were also examined using HR-MS analysis. An adsorption-photocatalytic synergistic reaction mechanism was postulated, in addition to TOC testing and active species detection. The combination of cellulose and LDH is proposed in this work as a potential strategy for the efficient removal of harmful pollutants from wastewater., Competing Interests: Declaration of competing interest The author declares that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

It is important to accomplish both photocatalytic efficiency and adsorption capacity in the catalyst to produce a highly effective photocatalyst for complete dye removal from wastewater. In the current investigation, TiO 2 and fly ash-TiO 2 composites (0.5-5 wt%) were fabricated by sol-gel and wet-impregnation process, and their catalytic performance was evaluated for the effective adsorption and photocatalytic degradation of fuchsin blue dye. The catalysts were characterized by XRD, UV-DRS, SEM, EDS, RAMAN spectroscopy, and N 2 adsorption analysis Adsorption and degradation studies were conducted to investigate factors such as pH (2 - 10), adsorbent dose (1-9 mg), contact time (30-180 min), and initial adsorbate concentration (5-30 mg/L) to eradicate fuchsin dye from water. The 5 wt% fly ash-TiO 2 catalyst showed a maximum capacity for adsorption of 20.32 mg/g and 76% removal of fuchsin dye. The Langmuir isotherm model fitted well to the experimental data, whereas the adsorption process obeyed pseudo-first-order kinetics. When exposed to UV light, a 5 wt% fly ash-TiO 2 composite demonstrated maximum photocatalytic degradation of 88% after 180 min, followed by a pseudo-first-order kinetic model. The catalyst was easily reusable for five cycles without losing dye removal effectiveness., Competing Interests: Declarations. Ethics approval: This work adhered to all ethical prerequisites for research publications. There were no experiments on animals carried out. Consent to participate: This work was not based on any research on humans. Consent for publication: All authors actively engaged in this study, provided contributions to its content, and received updates on the progress of the article preparations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Photocatalytic degradation has emerged as one of the most efficient methods to eliminate toxic dyes from wastewater. In this context, graphitic nitride (g-C 3 N 4 ) loaded BiVO 4 nanocomposites (5 wt% g-CN@BiVO 4 and 10 wt% g-CN@BiVO 4 ) have been fabricated by the wet impregnation method, and their efficiency towards photocatalytic removal of rhodamine B have been investigated under visible light irradiation. These hybrid composites have been characterized by XRD, FESEM, HRTEM, EDS-mapping, UV-Vis DRS, DLS, XPS and BET, etc. The HRTEM images revealed that BiVO 4 has a decagonal shape covered by a layered nanosheet-like structure of g-C 3 N 4 . BET measurements suggest increasing the proportion of g-C 3 N 4 results enhancement of the specific surface area. Among different photocatalysts, the 10 wt% g-C 3 N 4 @BiVO 4 hybrid possesses the best catalytic activity with 86% degradation efficiency after 60 min of reaction time. The LC-MS studies suggest that the degradation reactions follow the de-ethylation pathway. Even after five cycles, the heterostructure shows only a 14% decrease in photocatalytic activity, confirming its stability. As a result, the binary composite can be regarded as a promising catalyst for the degradation of pollutants due to its ease of preparation, high stability and superior catalytic activity., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 Published by Elsevier Ltd.)

Graphene oxide (GO) has now emerged as one of the most promising materials in different areas such as photocatalysis, adsorption, and energy storage due to its high surface area, unique layered structure, etc. Among various types of precursors, anthracite coal has attracted a lot of attention nowadays as it affords GO a high concentration of sp 2 carbons resulting in high conductivity and superior absorbance in the visible region. In this report, we have prepared GO-TiO 2 nanocomposites as it is supposed to possess high photocatalytic activity owing to facile electron transmission from the conduction band of TiO 2 to the GO surface resulting in a much lower degree of electron-hole pair recombination. To boost the photocatalytic activity further, TiO 2 was coated with Ag nanoparticles as well. These hybrid structures were characterized by different analytical techniques, for example, XRD, HR-TEM, SEM, and Raman spectroscopy. The XRD pattern of these composites consists of characteristic peaks corresponding to GO, TiO 2 , and Ag. The HR-TEM studies confirm the presence of GO layers, cube-shaped TiO 2 , and spherical Ag nanoparticles. Phenol and 4-nitrophenol have been used as model pollutants to evaluate the photooxidation efficiencies under both UV and visible light irradiation. Under UV irradiation, the GO/Ag-TiO 2 ternary nanocomposite shows better photooxidation efficiency (62%) compared to Ag-TiO 2 (38%), GO-TiO 2 (9%), GO (17%), and TiO 2 (8%) toward phenol degradation. The GO/Ag-TiO 2 is also having the highest photocatalytic activity toward the removal of phenol under visible light irradiation (34%). The ternary heterostructure (85%) also possesses superior photooxidation activity compared to Ag-TiO 2 (44%) and GO-TiO 2 (71%) toward the degradation of p-nitrophenol under UV light radiation for 60 min. The above observation reveals that the cooperative effect of Ag, TiO 2 , and GO is playing a crucial role to result in the high photooxidation activity of the GO/Ag-TiO 2 hetero-nanocomposites., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

One of the most omnipresent problems to the environment is the efficient removal of textile dyes and non-steroidal drugs from wastewater. For this purpose, renewable, sustainable, and biodegradable biopolymers are used. In this study, starch (S) modified NiFe-layered double hydroxide (LDH) composites were successfully synthesized by the co-precipitation method and have been examined as a catalyst for the effective adsorption of reactive blue 19 dye, reactive orange 16 dye, and piroxicam-20 NSAID from wastewater and photocatalytic degradation of reactive red 120 dye. The physicochemical properties of the prepared catalyst were assessed by XRD, FTIR, HRTEM, FE-SEM, DLS, ZETA, and BET. The coarser and more porous micrographs are shown in FESEM, indicating the homogeneous dispersion of layered double hydroxide on starch polymer chains. The S/NiFe-LDH composites have a slightly greater S BET (6.736 m 2 /g) than NiFe LDH (4.78 m 2 /g). The S/NiFe-LDH composite shows remarkable ability in the removal of reactive dyes. The band gap value of NiFe LDH, S/NiFe LDH (0.5:1), and S/NiFe LDH (1:1) composites was calculated as 2.28 eV, 1.80 eV, and 1.74 eV, respectively. The q max assessed from Langmuir isotherm for removal of piroxicam-20 drug, reactive blue 19 dye, and reactive orange 16 was 2840 mg/g, 149.47 mg/g, and 182.4 mg/g, respectively. The activated chemical adsorption without product desorption is predicted by the Elovich kinetic model. With reactive red 120 dye, S/NiFe-LDH shows photocatalytic degradation within 3 h of irradiation of visible light with 90% removal efficiency and follows a pseudo-first-order kinetic model. The scavenging experiment confirms the involvement of electrons and holes in photocatalytic degradation. With a little decline in adsorption capacity up to five cycles, starch/NiFe LDH was easily regenerated. So, the suitable adsorbent required for wastewater treatment is nanocomposites of LDHs and starch as they enhance the chemical and physical attributes of the composite structure with greater absorption capabilities., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The biophysical properties of DNA-modified Au nanoparticles (AuNPs) have attracted a great deal of research interest for various applications in biosensing. AuNPs have strong binding capability to the phosphate and sugar groups in DNA, rendering unique physicochemical properties for detection of metal ions. The formation of Au-DNA nanocomposites is evident from the observed changes in the optical absorption, plasmon band, zeta potential, DLS particle size distribution, as well as TEM and AFM surface morphology analysis. Circular dichroism studies also revealed that DNA-functionalized AuNP binding caused a conformational change in the DNA structure. Due to the size and shape dependent plasmonic interactions of AuNPs (33-78 nm) with DNA, the resultant Au-DNA nanocomposites (NCs) exhibit superior fluorescence emission due to chemical binding with Ca 2+ , Fe 2+ and Mg 2+ ions. A significant increase in fluorescence emission (λ ex = 260 nm) of Au-DNA NCs was observed after selectively binding with Mg 2+ ions (20-800 ppm) in an aqueous solution where a minimum of 100 ppm Mg 2+ ions was detected based on the linearity of concentration versus fluorescence intensity curve (λ em = 400 nm). The effectiveness of Au-DNA nanocomposites was further verified by comparing the known concentration (50-120 ppm) of Mg 2+ ions in synthetic tap water and a real life sample of Gelusil (300-360 ppm Mg 2+ ), a widely used antacid medicine. Therefore, this method could be a sensitive tool for the estimation of water hardness after careful preparation of a suitably designed Au-DNA nanostructure.

A series of novel Au x Cd 1-x S materials (x=0, 0.01, 0.02, 0.03, 0.05, 0.07, 0.1) were prepared and their optical properties, structural-surface morphology, and photocatalytic activity for oxidation and reduction reactions under visible-light irradiation were studied. X-ray diffraction confirmed the shrinkage of the hexagonal crystal structure of CdS; the lattice parameters decreased as a=4.190→4.072 Å and b=c=6.790→6.635 Å with increased loading (1-10 mol %) of the Au 3+ dopant. Optical spectra of Au x Cd 1-x S revealed a significant red-shift (485→538 nm) of the absorption onset and band edge emission (506→530 nm) with notable quenching in photoluminescence. The bandgap energy decreases (2.71→2.41 eV) with increasing Au 3+ doping of the CdS nanorods along with considerable shifting of valence band (+1.13→+1.04 eV) and conduction band positions (-1.58→-1.36 eV) versus NHE. The surface area of bare CdS (90.56 m 2  g -1 ) is gradually reduced to 12.32 m 2  g -1 with increasing Au 3+ doping content. The photocatalytic activity considerably improves with doping, where the Au 0.1 Cd 0.9 S composite displays the highest levels of photooxidation (95 %) of 0.5 mM salicyldehyde and reduction of 5 mM m-dinitrobenzene to m-nitroaniline (44 %) and m-phenylenediamine (52 %) relative to bare CdS (50 %) probably due to the homogeneous dispersion of Au 3+ ions throughout CdS crystal, their superior band-energetics for facile charge-separation and better photostability., (Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)