Microwave-assisted hydrothermal synthesis of graphene based Au–TiO<sub>2</sub> photocatalysts for efficient visible-light hydrogen production

Zhang

Journal of Alloys and Compounds

et al. 2016

157

a b s t r a c t N-doped TiO 2 nanowire/N-doped graphene (NeTiO 2 /NG) heterojunctions are fabricated by a simple hydrothermal method in a solution containing urea. In this hybrid structure, a three-dimensional hybrid photocatalyst was fabricated by using one-dimensional N-doped TiO 2 nanowires penetrating through twodimensional graphene nanosheets. Compared with TiO 2 nanowire/graphene and N-doped TiO 2 nanowire/ graphene composites, the NeTiO 2 /NG heterostructures demonstrate a better photocatalytic performance for the degradation of methylene blue under visible light irradiations, as well as displaying a better recyclability. It is found that the nitrogen atoms originated from the decomposition of urea were not only entered into the lattice of TiO 2 nanowires but also doped into the skeleton of graphene nanosheets. Results show that N doping expands the visible light absorption region of TiO 2 , and N-doped graphene additionally improves the separation and transportation of photogenerated electronehole pairs plus generating a higher photocurrent, which plays a critical role for enhancing the photocatalytic activity.

Section: Resultsmentioning

confidence: 75%

“…1c). The adsorptionedesorption isotherms of NeTiO 2 /NG, NeTiO 2 /G and TiO 2 /G exhibit typical IV nitrogen adsorption branches with a H3 hysteresis loop at a relative pressure between 0.5 and 1.0, indicating the presence of a mesoporous structure (2e50 nm) [46,49]. The pore size (Fig.…”

Section: Resultsmentioning

confidence: 99%

Hydrothermal synthesis of N-doped TiO2 nanowires and N-doped graphene heterostructures with enhanced photocatalytic properties

Zhang

Journal of Alloys and Compounds

et al. 2016

157

“…Chai and his coworkers [230,231] , and can be produced on a large scale at low cost [232][233][234]. Since the pioneering studies by Kamat and coworkers [235,236], semiconductor/graphene-based nanocomposites have attracted a lot of attention in different fields due to their good electron conductivity, large specific surface area and high adsorption [222,[237][238][239][240].…”

Section: Semiconductor/nano-carbon Heterojunctionsmentioning

confidence: 99%

Design and fabrication of semiconductor photocatalyst for photocatalytic reduction of CO2 to solar fuel

et al. 2014

Self Cite

The shortage of fossil fuels and the disastrous pollution of the environment have led to an increasing interest in artificial photosynthesis. The photocatalytic conversion of CO 2 into solar fuel is believed to be one of the best methods to overcome both the energy crisis and environmental problems. It is of significant importance to efficiently manage the surface reactions and the photo-generated charge carriers to maximize the activity and selectivity of semiconductor photocatalysts for photoconversion of CO 2 and H 2 O to solar fuel. To date, a variety of strategies have been developed to boost their photocatalytic activity and selectivity for CO 2 photoreduction. Based on the analysis of limited factors in improving the photocatalytic efficiency and selectivity, this review attempts to summarize these strategies and their corresponding design principles, including increased visible-light excitation, promoted charge transfer and separation, enhanced adsorption and activation of CO 2 , accelerated CO 2 reduction kinetics and suppressed undesirable reaction. Furthermore, we not only provide a summary of the recent progress in the rational design and fabrication of highly active and selective photocatalysts for the photoreduction of CO 2 , but also offer some fundamental insights into designing highly efficient photocatalysts for water splitting or pollutant degradation. INTRODUCTIONThe shortage of the energy supply and the problem of disastrous environmental pollution have been recognized as two main challenges in the near future [1]. It is a better way to efficiently and inexpensively convert solar energy into chemical fuels by developing an artificial photosynthetic (APS) system because solar fuels are high density energy carriers with long-term storage capacity. The most important and challenging reactions in APS-the photocatalytic water splitting into H 2 and O 2 (water reduction and oxidation) [2][3][4] and photoreduction of CO 2 to solar fuel, such as CH 4 and CH 3 OH [5,6] have been extensively studied since the photocatalytic water splitting on TiO 2 electrodes was discovered by Honda and Fujishima in 1972 [7]. The photocatalytic reduction of CO 2 by means of solar energy has attracted growing attention in the recent years, which 1 State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China 2 College of Science, South China Agricultural University, Guangzhou 510642, China 3 Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia * Corresponding author (email: jiaguoyu@yahoo.com) is also believed to be one of the best methods to overcome both global warming and energy crisis [8]. However, it is also generally thought that photocatalytic CO 2 reduction is a more complex and difficult process than H 2 production due to preferential H 2 production and low selectivity for the carbon species produced [9,10]. The progress achieved in the photoreduction of CO 2 is still far behind that in wate...

Topics in Current Chemistry

“…Furthermore, it was shown that Au{111}/TiO 2 exhibited the lowest apparent activation energy for hydrogen evolution. Wang et al prepared graphenebased Au/TiO 2 photocatalysts and investigated photocatalytic hydrogen generation under visible light irradiation [193]. They could show that graphene modified Au/TiO 2 had a 1.7-fold higher activity than the analogous Au/TiO 2 sample under [195].…”

Section: Water Splittingmentioning

confidence: 98%

Surface Plasmon-Assisted Solar Energy Conversion

Dodekatos

Schünemann

Tüysüz

2015

The utilization of localized surface plasmon resonance (LSPR) from plasmonic noble metals in combination with semiconductors promises great improvements for visible light-driven photocatalysis, in particular for energy conversion. This review summarizes the basic principles of plasmonic photocatalysis, giving a comprehensive overview about the proposed mechanisms for enhancing the performance of photocatalytically active semiconductors with plasmonic devices and their applications for surface plasmon-assisted solar energy conversion. The main focus is on gold and, to a lesser extent, silver nanoparticles in combination with titania as semiconductor and their usage as active plasmonic photocatalysts. Recent advances in water splitting, hydrogen generation with sacrificial organic compounds, and CO2 reduction to hydrocarbons for solar fuel production are highlighted. Finally, further improvements for plasmonic photocatalysts, regarding performance, stability, and economic feasibility, are discussed for surface plasmon-assisted solar energy conversion.