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In this study, an attempt was made to pretreat seawater using polyethersulfone (PES) mixed matrix membranes (MMMs) incorporated with titania-based binary metal oxides. Two different titania-based binary metal oxides were prepared, namely titania-zirconia (TiZr) and titania-zinc oxide (TiZn). The influence of hydrophilic and negatively charged sulfonated poly(ether ether ketone) (SPEEK) polymer as additive of PES MMMs was also studied. Morphological and elemental analysis revealed that both ZrO2 and ZnO were well dispersed in the as-prepared binary metal oxide TiZr and TiZn, respectively.. Thermogravimetry analysis indicated the good compatibility of TiZr and TiZn with the SPEEK/PES polymer. The binary metal oxide incorporated SPEEK/ PES MMMs exhibited improved hydrophilic properties with a low water contact angle of 57 ± (0.6). SPEEK/PES MMMs incorporated with 0.5 wt% TiZr exhibited the highest permeability of 3.11 × 10−7 ± (0.2) m/skPa. Seawater pretreatment performance of membranes evaluated using natural organic matters containing high salinity feed water. TiZr and TiZn incorporated SPEEK/ PES MMMs exhibited 95% rejection for humic acid. SPEEK/PES MMMs loaded with 0.5 wt% TiZr also showed the highest water flux and 87% water recovery within 90 min of seawater filtration. Both PES/SPEEK/TiZr and PES/SPEEK/ TiZn MMMs exhibited superior antibacterial activity. [ABSTRACT FROM AUTHOR]

Facile ionothermal method has been employed to synthesize One-dimensional (1-D) mixed phase TiO2 nanorods (NRs) using ionic liquid as the reaction medium. The PXRD pattern reveals the formation of mixed phase TiO2 having 68.3% of anatase and 31.7% rutile phase with average crystallite size of ~ 10 nm. TEM images depict the average thickness of TiO2 NRs are in the range 50-100 nm. The 1-D mixed phase TiO2 NRs showed 5 times better hydrogen production activity than P-25 in the water-glycerol mixture under solar light irradiation. The reason could be the synergetic effect and unique optical properties of 1-D anatase-rutile TiO2 mixed-phase system. [ABSTRACT FROM AUTHOR]

Here we report on Bi2O3 clusters immobilized on anatase TiO2 nanostructures for an enhanced rate of photocatalytic H2 evolution. Structural, morphological, and optical properties of the Bi2O3@TiO2 nanocomposite (BT) were characterized by a series of techniques including X-ray diffraction, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy and electrochemical impedance spectroscopy. The catalytic H2 evolution experiments were carried out under different light sources: natural solar light, LED UV (365 ± 5 nm) and LED visible (420 ± 5 nm) light source. Under the solar light a pristine anatase TiO2 nanostructured (TNS) catalyst generated 4.20 mmol h−1 g−1, whereas in the presence of Bi2O3@TNS showed much higher H2 production 26.02 mmol h−1 g−1. The photocatalytic activity of the BT and its reproducible performance for five recycles is ascribed to an efficient separation of photogenerated charge carriers. A plausible reaction mechanism for the H2 generation is proposed. [ABSTRACT FROM AUTHOR]

Mixtures of straight and defect-free multiwalled carbon nanotubes (MWCNTs), single walled carbon nanohorns (SWCNHs), and multiwalled carbon nanohorns (MWCNHs) were prepared by the arc discharge method. Functionalized Carbon Nanotubes (FCNTs) composed of MWCNTs, MWCNHS and SWCNHs were obtained using acid functionalization process. TiO2/FCNTs (CTP) nanohybrid photocatalysts were obtained with different amounts of FCNTs (2-20 wt%), by wet impregnation method. The photocatalytic activity of both pristine TiO2 as well as the nanohybrids were studied in aqueous glycerol solution under solar irradiation. Reaction parameters such as amount of catalyst and amount of FCNTs in nanohybrids were optimized to ensure high rates of H2 production. With a relatively low amount of pristine TiO2, a high rate of H2 production of 2134 μmol h−1 gcat−1 has been obtained and is likely due to several factors such as well dispersed catalyst, reduced particle-particle agglomeration, resulting in enhanced light absorption (less light shielding), improved separation of charge carriers and utilization for red-ox reactions. Even better results were obtained with the use of nanohybrid catalysts. The enhanced photocatalytic activities of the nanohybrid catalysts are ascribed to the synergetic effects of FCNTs that minimize light reflection which promotes enhanced solar light sensitization, good dispersion of the catalysts in the reaction solution, and improved surface-interface reactions of photogenerated charge carriers. In the present study 10 wt% FCNTs in nanohybrid (CTP-10) exhibited superior photocatalytic activity for H2 generation, nearly 3 times higher than that of pristine TiO2 catalyst. The CTP-10 photocatalyst exhibited photostability under the experimental conditions studied. The nanohybrid photocatalysts were characterized in order to confirm the crystal structure, morphology, surface chemical composition and optical properties. The present work demonstrates the unique beneficial photocatalytic properties of carbon nanotubes and nanohorn mixtures in nanohybrid photocatalysts, for enhanced H2 production. [ABSTRACT FROM AUTHOR]

Ternary nanohybrids based on mesoporous graphitic carbon nitride (g-C 3 N 4 ) were synthesized and presented for developing stable and efficient Hydrogen (H 2 ) production system. Based on photocatalytic activity, optimization was performed in three different stages to develop carbon nanotubes (CNTs) and WO 3 loaded g-C 3 N 4 (CWG-3). Initially, the effect of exfoliation was investigated, and a maximum specific surface area of 100.77 m 2 /g was achieved. 2D-2D interface between WO 3 and g-C 3 N 4 was targeted and achieved, to construct a highly efficient direct Z-scheme heterojunction. Optimized binary composite holds the enhanced activity of about 2.6 folds of H 2 generation rates than the thermally exfoliated g-C 3 N 4 . Further, CNT loading towards binary composite in an optimized weight ratio enhances the activity by 6.86 folds than the pristine g-C 3 N 4 . Notably, optimized ternary nanohybrid generates 15,918 μmol h -1 . g -1 cat of molecular H 2 , under natural solar light irradiation with 5 vol% TEOA as a sacrificial agent. Constructive enhancements deliver remarkable H 2 production and dye degradation activities. Results evident that, the same system can be useful for pilot-scale energy generation and other photocatalytic applications as well., Competing Interests: Declaration of competing interest 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., (Copyright © 2022 Elsevier Ltd. All rights reserved.)