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This study is focused on synthesis of highly efficient Titania/reduced Graphene Oxide (TiO2/rGO) nanocomposites by means of simple hydrothermal technique. The TiO2/rGO were synthesized in different ratios of 0.5, 1.0, 2.0, and 3% by varying the concentration of rGO while the concentration of TiO2 was kept constant and the obtained samples were designated as TrG0.5, TrG1, TrG2, and TrG3 respectively. Different characterization techniques (SEM, TEM, HRTEM, XRD, EDX, TGA, UV-DRS, PL, EIS, and BET) showed high crystallinity, small crystallite size (18.4 nm), high thermal stability, high purity, low band gap energy (Eg = 3.12 eV), and high surface area (65.989 m2/g) for the as-synthesized TiO2/rGO nanocomposite. The efficiencies of TiO2/rGO were determined in terms of brilliant green (BG) dye degradation in aqueous media under UV light. The results revealed that 2% TiO2/rGO (TrG2) showed high efficiency for BG degradation with the kapp of 0.023 min−1 compared to TiO2 alone (kapp of 0.006 min−1). The rate of BG degradation was further synergised by the addition of peroxymonosulfate (PMS) to the system. The degradation of BG was improved to 99.4% by the incorporation of PMS in aqueous media compared to TrG2 alone. Furthermore, the degradation of BG was also examined in various media (neutral, acidic, and basic). The results revealed that by increasing pH of the medium from 3.85 to 8.2 the degradation of BG was enhanced from 99.4 to 99.9% with the corresponding kapp of 0.0602 min−1. Moreover, the photocatalytic degradation of BG followed the pseudo-first-order kinetics. Radical scavenging experiments showed that ●OH and SO4●– were the main species responsible for the degradation of BG under UV light. Besides, for determining the efficiency of as-synthesized TrG2/PMS system, the degradation of BG was also performed in various water types (distilled water, tape water, synthetic wastewater, and industrial wastewater). The degradation products (DPs) of BG and their corresponding pathways were proposed, accordingly. [ABSTRACT FROM AUTHOR]

A novel and efficient solar light responsive multi layered highly porous MXene-based Ti 3 C 2 /TiO 2 @Bi 2 O 3 photocatalyst was synthesized by hydro/solvothermal technique. The optimized band gap (2.09 eV), high surface area (28.39 m2/g), schottky and p-n junctions remarkably enhanced the effectiveness of TTB20 in the solar region. The degradation of sulfadiazine (SDZ) by TTB20 under solar light was enhanced from 76.60 % to 97.40 % when coupled with 0.5 mM peroxymonosulfate (HSO 5 –) at an irradiation time of 30 min. The radical scavenging investigations indicated that SO 4 •−, O 2 •− and h+ are primarily engaged in photocatalytic activity. Moreover, the TTB20 sample showed promising activity against E-coli. In addition, the TTB20 sample displayed a remarkable 4.15-fold higher photocatalytic H 2 evolution rate than the TTB0 sample. Thus, the present study suggests that TTB20/HSO 5 –/solar light is an auspicious approach for addressing environmental pollution, health issues and energy crises. [Display omitted] • Highly porous multi-layered Ti 3 C 2 /TiO 2 @Bi 2 O 3 -based Mxene heterojunction was synthesized by hydro/solvothermal protocol. • Schottky and p-n junctions remarkably reduced e–/h+ recombination. • A dual strategy was adopted for combating antibiotic-resistance bacteria. • SO 4 •−, O 2 •− and h+ are primarily involved in photocatalytic activity. • A promising photocatalytic H 2 evolution rate was recorded. [ABSTRACT FROM AUTHOR]

Abstract In the present study the synthesis of an inexpensive solar light responsive Co2+ and Fe3+ co-doped TiO 2 (Co Fe TiO 2) for efficient photocatalytic degradation of ofloxacin (OFL) in addition to its excellent activity as peroxidase mimics has been reported. The as-synthesized material was fully investigated morphologically and structurally by X-ray diffraction (XRD) analysis, field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) and UV diffuse reflectance spectroscopy (UV-DRS). The morphology of the as-synthesized Co Fe TiO 2 appeared to be more dispersed, porous and uniform. The UV-DRS analysis showed that the band gap of the as-synthesized TiO 2 , Fe TiO 2 , Co TiO 2 , Co Fe TiO 2 was measured as 3.31, 3.22, 3.15 and 3.04 eV, respectively. The pilot scale experiments were conducted in a simple non-concentrating solar photoreactor by using the as-synthesized Co Fe TiO 2 having total volume of 5 L. To synergize the photocatalytic process the photocatalytic reactor was added with peroxymonosulfate (HSO 5 −). The effect of various process parameters like [HSO 5 −] 0 , flow rate and [Co Fe TiO 2 ] 0 were optimized. The assessment of degradation products (DPs) of OFL and then their toxicity analysis suggested the as-synthesized Co Fe TiO 2 provides a safe route for the solar light induced photocatalytic degradation of OFL. The as-synthesized Co-Fe TiO 2 was also applied as novel peroxidase mimetic that can catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) when H 2 O 2 serves as oxidant. The results showed that the color response and the peroxidase like response of Co Fe TiO 2 highly rely on the concentration of H 2 O 2 and thus the as-synthesized material can successfully be applied for the calorimetric sensing of H 2 O 2. Graphical abstract Unlabelled Image Highlights • Solar light driven photocatalysis of ofloxacin at pilot scale level. • Lowering the band gap of TiO 2 by co-doping with Co2+ and Fe3+. • Fifteen (15) new photocatalytic degradation byproducts of OFL were found. • Toxicity assessment revealed that some of the DPs are more toxic than OFL. • In situ peroxidase like behavior of Co Fe TiO 2 was found. [ABSTRACT FROM AUTHOR]

Abstract This study presents the synthesis of a novel Mn2+ and Co2+ co-doped TiO 2 (Mn-Co-TiO 2) for the photocatalytic degradation of enoxacin (ENX) under solar light irradiation. The as-synthesized photocatalysts were fully characterized by X-ray diffraction (XRD) analysis, field emission-scanning electron microscopy (FE-SEM), and UV-diffuse reflectance spectroscopy (UV-DRS). The structural appearance of the Mn-Co-TiO 2 suggests porous cylindrical type morphology. Moreover, the co-doping of Mn2+ and Co2+ has successfully reduced the band gap of TiO 2 from 2.81 eV to 2.10 eV. Applying Langmuir Hinshelwood kinetic model, the photocatalytic degradation of ENX by Mn-Co-TiO 2 followed pseudo-first-order kinetics. A total of twelve (12) DPs of ENX were identified by UPLC/MS-MS. The natural water constituents such as CO 3 2−, HCO 3 −, Cl− and Fe3+ had great influence on the photocatalytic degradation of ENX by Mn-Co-TiO 2 under solar light irradiation. The as-synthesized Mn-Co-TiO 2 showed appreciable results for the photocatalytic degradation of ENX in synthetic wastewater (SWW) and real wastewater (RWW) samples. Furthermore, the toxicity assessment of ENX and its DPs towards aquatic organisms (i.e., fish, daphnia and green algae) was measured which are helpful for the practical implementation of this technology for wastewater treatment. The Mn-Co-TiO 2 materials also showed good peroxidase-like activity towards the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H 2 O 2 and followed Michaelis-Menten kinetics. Graphical abstract Unlabelled Image Highlights • Efficient Solar light driven photocatalysis of Enoxacin. • Narrowing the band gap of TiO 2 by co-doping with Mn2+ and Co2+ • Total of twelve (12) new photocatalytic degradation byproducts of ENX were found. • Toxicity assessment revealed that some of the degradation byproducts are more toxic than ENX. • Additional peroxidase like activity of Mn/Co-TiO 2 was found. [ABSTRACT FROM AUTHOR]

Ti3+ self-doped Fe 2 O 3 /TiO 2 ultra-thin nanoflakes have been fabricated on Ti-substrate by a facile hydrothermal route. The high solar light harvest by Ti3+ and oxygen vacancies makes Ti3+ self-doped Fe 2 O 3 /TiO 2 ultra-thin nanoflakes an attractive candidate for photo-activation of peroxymonosulfate (HSO 5 −) for the degradation of naphthalene (NAP). The Fe 2 O 3 /TiO 2 ultra-thin nanoflakes synthesized with 0.053 M of FeCl 3 (TF3) exhibited high concentrations of Ti3+ and oxygen vacancies. TF3/ HSO 5 −/solar light system showed substantial increases in the degradation of NAP with k app value of 0.1384 min–1 compared to 0.057 min–1 when no HSO 5 − was added to the system. The proposed system also showed appreciable degradation of NAP in real water samples. Based on scavenger studies, SO 4 •−, •OH, h+ and O 2 •− are generated in the reaction system. Importantly, the toxicity results indicated that the proposed system (TF3/HSO 5 −/solar light) is an efficient treatment process for detoxifying water contaminated with NAP. [Display omitted] • Ultra-thin Ti3+ self-doped Fe 2 O 3 /TiO 2 nanoflakes were synthesized on Ti-substrate. • The ultra-thin nanoflakes exhibited high concentration of Ti3+ and oxygen vacancies. • Synergy of HSO 5 − greatly accelerated the degradation performance of TF3 material. • ESR analysis confirmed the formation of •OH and SO 4 •− by TF3/HSO 5 −/solar light. • ECOSAR results indicated proposed system can detoxify waters contaminated with NAP. [ABSTRACT FROM AUTHOR]

In the present study, a novel TiO2/Ti film with enhanced {001} facets was synthesized by the hydrothermal technique followed by calcination for studying the removal of bezafibrate (BZF), from an aqueous environment. The synthesized photocatalyst was characterized by FE-SEM, XRD, HR-TEM, and PL-technique. The second-order rate constant of •OH with BZF was found to be 5.66 × 109 M-1 s-1. The steady state [•OH] was measured as 1.16 × 10-11 M, on the basis of oxidation of terephthalic acid. The photocatalytic degradation of BZF followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model (k1 = 2.617 mg L-1 min-1 and k2 = 0.0796 (mg L-1)−1). The effects of concentration and the nature of various additives including inorganic anions (NO3-, NO2-, HCO3-, CO32-, Cl-) and organic species (fulvic acid) and initial solution pHs (2, 4, 6, 9) on photocatalytic degradation of BZF were investigated. It was found that the nature and concentration of studied additives significantly affected the photocatalytic degradation of BZF. The efficiency of the photocatalytic degradation process in terms of electrical energy per order was estimated. Degradation schemes were proposed on the basis of the identified degradation byproducts by ultraperformance liquid chromatography. [ABSTRACT FROM AUTHOR]

This study demonstrates the synthesis of highly hydrophilic poly(vinylidene fluoride) composite membranes incorporated with Titania (TiO 2) nanotubes (PVDF/TNT) and then its photocatalytic applications were explored for effective degradation of brilliant green (BG) dye. The membranes were fabricated through phase inversion method using poly(vinylidene fluoride) (PVDF) as matrix, Titania nanotubes (TNT) with different concentrations (0–2 wt%) as filler and poly(vinylpyrrolidone) as pore former. Successful fabrication of composite membranes (PVDF/TNT) was confirmed by using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Membrane properties were studied using contact angle, tensile strength, solvent content, pure water flux, bovine serum albumin (BSA) rejection, antifouling properties, porosity and shrinkage ratio. The degradation results suggested that the fabricated membrane can effectively be applied as a heterogenous photocatalyst for the degradation of BG. The results confirm that the dispersion of TNTs increases the antifouling properties of membranes to a maximum value. A minimum pore volume 0.34 cc g−1, pore size 28.4 nm and maximum surface area 142 m2 g−1 were obtained with loading 1.5 wt% TNTs in PVDF membranes, which can degrade BG up to 42% compared to 13% in the absence of fabricated membrane after 90 min of reaction time. The photocatalytic degradation mechanism of BG by PVDF/TNT ultrafiltration membranes showed that OH is mainly involved in the degradation process. The degradation byproducts of BG were determined using LC–MS/MS and accordingly degradation pathways were proposed. [ABSTRACT FROM AUTHOR]

In this study, solar light responsive Bi 3+ and Fe 2+ doped ZnO were synthesized and used for photocatalytic degradation of norfloxacin (NOR), an emerging water pollutant. Analysis with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and UV–vis diffuse reflectance spectroscopy (DRS) confirmed coupling of dopants (i.e., Bi 3+ and Fe 2+ ) or co-dopants (Bi 3+ /Fe 2+ ) with ZnO and suggested small narrow size as well as highly crystalline and porous nature of the doped ZnO. Metal ions doping lowered band gap energy and inhibited recombination of electron-hole pair in the as-synthesized ZnO. Consequently, BiFe-ZnO showed enhanced photocatalytic activity and reusability, giving 80% removal of NOR as compared to 36% by un-doped ZnO at a reaction time of 120 min. The analysis with photoluminescence (PL) technique verified high yield of OH from solar light activation of BiFe-ZnO compared to Bi-ZnO, Fe-ZnO and ZnO. Performance of the as-prepared photocatalysts was promoted with the added HSO 5 − and increased with increasing [HSO 5 − ] 0 . Degradation of NOR by BiFe-ZnO with the added HSO 5 − was due to OH and SO 4 − and NOR showed high reactivity with OH and SO 4 − . The removal efficiency of NOR was inhibited using OH and SO 4 − scavengers. Photocatalytic activity of the as-synthesized photocatalysts with the added HSO 5 − was highly dependent on [NOR] 0 , [pH] 0 , co-existing ions, and natural organic matter. Degradation pathways were suggested from the pattern of NOR degradation and identified transformation products. The mineralization of NOR as well as formation of non-toxic end product suggests co-doped ZnO with added HSO 5 − to be a potential technology for treating antibiotics contaminated water. [ABSTRACT FROM AUTHOR]

• Deep eutectic solvent and nitrogen-doping enhanced stability and efficiency of Ceria. • Removal of sulfamethaxazole was inhibited in the presence of h vb + and OH scavengers. • Second-order rate constant of sulfamethaxazole with OH was calculated. • Degradation pathways were established and estimated toxicities of SMX and its DPs. • Ceria NPs were highly active against Gram-positive and Gram-negative bacteria. In this study, highly crystalline, mesoporous, small sized, stable, and efficient nitrogen-doped (N-doped) Ceria nanoparticles were synthesized using deep eutectic solvent (DES) and used for the photocatalytic degradation of sulfamethaxazole (SMX), a widely used human medication and emerging water contaminant. The N-doped Ceria resulted in 96% removal of SMX versus 59% by Ceria under solar irradiation at 150 min time using [SMX] 0 = 10 mg/L and [Ceria] 0 = [N-doped Ceria] 0 = 0.5 g/L. The solar irradiation of the photocatalysts produced OH which was proved with electron spin resonance (ESR) spectroscopy and radical scavenger studies and the resulting OH caused the degradation of SMX. The OH showed high second-order rate constant with SMX, e.g., 4.9 × 109 M−1 s−1. The photocatalytic degradation of SMX was influenced by pH, concentrations of SMX and photocatalysts, inorganic anions, and natural organic matter. The kinetics of the photocatalytic degradation of SMX was found to be pseudo-first-order. The SMX degradation resulted into several products which were identified by UPLC-MS/MS and the resulting products were used to establish degradation pathways of SMX. The synthesized Ceria and N-doped Ceria also showed good antimicrobial activities towards Staphylococcus aureus and Escherichia coli. The treatment of SMX showed high reusability of N-doped Ceria, low leaching of cerium ions into reaction solution, and high decline in toxicity of SMX which suggests high potential of the synthesized nanoparticles towards SMX degradation. [ABSTRACT FROM AUTHOR]

Abstract Synthesis of nanoparticles (NPs) through "green" chemistry is an exciting area of research with wide applications. Trianthema portulacastrum's extract containing greater amount of reducing agents has been explored first time for the synthesis of ZnO-NPs that characterized with UV/Vis, XRD, FT-IR, SEM,EDX, HR-TEM and XPS. The particles of ZnO-NPs are crystalline and having the size in the range of 25–90 nm. The cell viability of ZnO-NPs was studied using Mouse pre-osteoblast cell line MC3T3-E1 sub-clone 14 cells which confirmed its biocompatibility that render for biomedical applications. The antibacterial properties were evaluated against Staphylococcus aureus and Escherichia coli which showed high potency of synthesized ZnO-NPs against these species. The antifungal activities of ZnO-NPs were screened against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus of fungal species. The antioxidant activity of the as-synthesized NPs was also studied using DPPH (2, 2-diphenyl-1-picrylhydrazyl) substrate. The ZnO-NPs were evaluated for catalytic activity through degradation of Synozol Navy Blue-KBF textile dye using solar irradiation that causes 91% degradation of the dye in 159 min. Mechanistic pathways for the degradation of Synozol Navy Blue-KBF dye using ZnO-NPs were also proposed from the pattern of the degradation of the dye and the resulting by-products. The results concluded that the ZnO-NPs synthesized by green method have high biological and photocatalytic applications. Graphical Abstract Unlabelled Image Highlights • Greener synthesis of Zinc Oxide Nanoparticles using Trianthema portulacastrum Extract. • Characterizations of ZnO-NPs by physical techniques like, XRD, FT-IR, SEM, HRTEM and XPS. • Antibacterial, antifungal and antioxidant application of green Synthesized ZnONPs. • use of ZnONPs to enhanced the photocatalytic activities of synozol navy blue K-BF water soluble dyes. • solar radiation, mechanistic investigation of synozol navy blue K-BF water soluble dyes. [ABSTRACT FROM AUTHOR]