Graphene-TiO2 Composite Photocatalyst with Enhanced Photocatalytic Performance

Pt position determining efficiency and stability for photocatalytic toluene degradation over Pt decorated TiO2

Highly durable photocatalytic degradation of gas toluene pollutants is a great challenge due to the easy deactivation of photocatalysts. Herein, we synthesized the Pt embedded at interface of TiO2 nanocomposites (TiO2/Pt/TiO2) and Pt exposed on the surface of TiO2 nanocomposites (Pt/TiO2/TiO2) to investigate the effect of Pt position on the photocatalytic performance of toluene degradation. It was found that the Pt-exposed samples showed inactivation as the reaction progressed because carbonaceous intermediates such as phenol and benzoic acid were observed to be deposited on the exposed Pt to restrain the role of Pt in electron transfer for the production of reactive oxygen species. Whereas, Pt-embedded nanocomposites had excellent activity and stability for toluene degradation and CO2 production more than 60 h. This was attributed to the protective effect of the TiO2 outerlayer. The embedded Pt was not easily poisoned by the degradation intermediates, resulting in a good electron transfer and the continuous production of reactive oxygen species for photocatalytic reaction. Therefore, this work provides an efficient approach for designing of the stability of metal-decorated photocatalyst for the highly durable photocatalytic performance.

Effect of indium (III) doping on Ag3PO4 catalyst stabilization and its visible light photocatalytic activity toward toxic dyes in water

Indium(III)-doped Ag3PO4 (In-AgP) catalysts at different weight percentages were elaborated by co-precipitation and subjected to XRD, SEM, UV-vis DRS, and FTIR characterization. The prepared catalysts were of spherical morphology and their diameters depends on doping dosage. The whole materials crystallize in a centered cubic system with a slight dissimilation in the positions of the characteristic peaks as a function of indium dosage. The photocatalytic performance of the catalysts under visible light was investigated in the photocatalytic degradation of anionic dye (methyl orange (MO)) and cationic dye (auramine O (AO)) in moderate acid, neutral, and basic pH conditions. Results showed more selectivity to MO than AO. Furthermore, indium-doped samples are more active in the acidic medium than the pure Ag3PO4 (AgP), and 10%In-AgP catalyst presents the highest activity. The degradation efficiency reached 99 % in 60 min for MO and in 180 min for AO. In addition, a high recycling stability was achieved and the catalyst retains its degradation capacity above 99 % after five cycles.

Photoelectrocatalytic properties and mechanism of rhodamine B degradation using a graphene oxide/Ag3PO4/Ni film electrode

GO/Ag₃PO₄/Ni thin film electrodes prepared by composite electrodeposition show excellent photoelectrocatalytic performance and a photoelectric synergistic effect.

Preparation of Multicycle GO/TiO2 Composite Photocatalyst and Study on Degradation of Methylene Blue Synthetic Wastewater

A series of composite photocatalysts were prepared by using graphene oxide (GO) prepared by modified Hummers method and TiO2 hydrogel prepared by using butyl titanate as raw materials. The composite photocatalyst was characterized through scanning electron microscope（SEM）, x ray diffraction （XRD）, and Raman spectroscopy, and the degradation effect of pure TiO2 and composite photocatalyst on methylene blue (MB) dye wastewater under different experimental conditions was studied. The results showed that TiO2 in composite photocatalyst was mainly anatase phase and its photocatalytic activity was better than pure TiO2. When the addition of GO reached 15 wt%, the photocatalytic activity was the highest. When 200 mg composite photocatalyst was added to 200 mL synthetic wastewater with a concentration of 10 mg/L and an initial pH of about 8, the degradation rate could reach 95.8% after 2.5 h. It is presumed that the photogenerated charges of GO/TiO2 composite photocatalyst may directly destroy the luminescent groups in the MB molecule and thus decolorize the wastewater, and no other new luminescent groups are generated during the treatment.

A facile solvothermal approach for the synthesis of novel W-doped TiO2 nanoparticles/reduced graphene oxide composites with enhanced photodegradation performance under visible light irradiation

W-Doped TiO₂ nanoparticles/reduced graphene oxide composites have been synthesized for the first time. The mechanism of their high photocatalytic activity for MB has been identified and discussed.

Effect of the graphene oxide reduction method on the photocatalytic and electrocatalytic activities of reduced graphene oxide/TiO2 composite

LSVs (50 mV s⁻¹) for hydrogen-reduced graphene oxide/TiO₂ composite in (i & ii) oxygen and (iii & iv) argon-saturated 0.5 M H₂SO₄ at 25 °C in the presence (ii & iv) and absence (i & iii) of 300 watt UV radiation.

Nanomaterials for membrane fouling control: accomplishments and challenges

We report a review of recent research efforts on incorporating nanomaterials-including metal/metal oxide nanoparticles, carbon-based nanomaterials, and polymeric nanomaterials-into/onto membranes to improve membrane antifouling properties in biomedical or potentially medical-related applications. In general, nanomaterials can be incorporated into/onto a membrane by blending them into membrane fabricating materials or by attaching them to membrane surfaces via physical or chemical approaches. Overall, the fascinating, multifaceted properties (eg, high hydrophilicity, superparamagnetic properties, antibacterial properties, amenable functionality, strong hydration capability) of nanomaterials provide numerous novel strategies and unprecedented opportunities to fully mitigate membrane fouling. However, there are still challenges in achieving a broader adoption of nanomaterials in the membrane processes used for biomedical applications. Most of these challenges arise from the concerns over their long-term antifouling performance, hemocompatibility, and toxicity toward humans. Therefore, rigorous investigation is still needed before the adoption of some of these nanomaterials in biomedical applications, especially for those nanomaterials proposed to be used in the human body or in contact with living tissue/body fluids for a long period of time. Nevertheless, it is reasonable to predict that the service lifetime of membrane-based biomedical devices and implants will be prolonged significantly with the adoption of appropriate fouling control strategies.

Synthesis and applications of graphene-based TiO(2) photocatalysts

Graphene is one of the most promising materials in the field of nanotechnology and has attracted a tremendous amount of research interest in recent years. Due to its large specific surface area, high thermal conductivity, and superior electron mobility, graphene is regarded as an extremely attractive component for the preparation of composite materials. At the same time, the use of photocatalysts, particularly TiO(2), has also been widely studied for their potential in addressing various energy and environmental-related issues. However, bare TiO(2) suffers from low efficiency and a narrow light-response range. Therefore, the combination of graphene and TiO(2) is currently one of the most active interdisciplinary research areas and demonstrations of photocatalytic enhancement are abundant. This Review presents and discusses the current development of graphene-based TiO(2) photocatalysts. The theoretical framework of the composite, the synthetic strategies for the preparation and modification of graphene-based TiO(2) photocatalysts, and applications of the composite are reviewed, with particular attention on the photodegradation of pollutants and photocatalytic water splitting for hydrogen generation.