8 research outputs found
Graphene Related Materials and Composites: Strategies and Their Photocatalytic Applications in Environmental Remediation
Photochemical reactions hold great promise in solving energy and environment related problems and likely contribute towards development of sustainable society. Despite of recent advancements, the inherent catalytic efficiency of conventional photocatalyst has been severely limited by myriad complexity associated with (i) ineffective light absorption in visible region, (ii) unproductive recombination’s of e−/h+ pair in excited state, and (iii) low chemical stability. Contemporary researches on photocatalysts that can be viable for commercial applications has yet to be realized. Graphene has attracted an immense research interests to enhancing the photocatalysts efficiency endowing from their unique optical and electronic properties and salient features such as surface area, mechanical strength and photochemical stability. In this book chapter, we discussed graphene related material (GRMs) to produce hybrid architectures or nanocomposites that can be used as efficient photocatalysts for the degradation of organic pollutants (dyes, pharmaceutical wastes, pesticides etc.) in wastewater. Lastly, we summarize the key insights in photocatalytic electron transfer mechanism, challenges and future perspective which help understand the rationale of GRMs in this field
CuO Quantum Dots Decorated TiO<sub>2</sub> Nanocomposite Photocatalyst for Stable Hydrogen Generation
An efficient and stable CuO-TiO<sub>2</sub> nanocomposite photocatalyst
was synthesized by using the simple molten-salt method. Characterization
by HR-TEM confirmed the existence of both TiO<sub>2</sub> and CuO
in the nanocomposite, revealing hexagonal TiO<sub>2</sub> nanoparticles
(NPs) with average particles size of 23.8 nm. CuO QDs decorated on
the TiO<sub>2</sub> surface were in the range of 2.2 to 4.6 nm. Photocatalytic
experiments for hydrogen (H<sub>2</sub>) production were carried out
under an LED (λ = 365 nm) lamp and natural solar light. The
effect of Cu-loading in CuO-TiO<sub>2</sub> NCs and synthesis time
were studied. The optimized CuO-TiO<sub>2</sub> NCs abbreviated as
CuT-4 and CuT-3 showed 27.7- and 9.0-fold superior rate of H<sub>2</sub> production compared to pristine TiO<sub>2</sub> NPs under LED and
solar irradiation, respectively. At optimal conditions, CuO-TiO<sub>2</sub> NCs demonstrated good photostability for H<sub>2</sub> evolution
during 75 h illumination under LED light. The experimental results
confirmed the cocatalytic role of CuO for improved H<sub>2</sub> generation
by a minimized recombination of excitons