Visible light driven type II heterostructures and their enhanced photocatalysis properties: a review

Abstract

Considerable efforts have been devoted to enhancing the photocatalytic activity and solar energy utilization of photocatalysts. The fabrication of type II heterostructures plays an important role in photocatalysts modification and has been extensively studied. In this review, we briefly trace the application of type II heterostructured semiconductors in the area of environmental remediation and water splitting, summarize major fabrication methods, describe some of the progress and resulting achievements, and discuss the future prospects. The scope of this review covers a variety of type II heterostructures, focusing particularly on TiO2 and ZnO based visible light driven type II 0D and 1D heterostructured photocatalysts. Some other low dimensional nanomaterials which have shown high-performance photocatalysis are also presented. We expect this review to provide a guideline for readers to gain a clear picture of fabrication and application of type II heterostructures.

Two-Dimensional Material Molybdenum Disulfides as Electrocatalysts for Hydrogen Evolution

“…In recent decades, the development of new energy sources has become a hot topic in academia [1][2][3][4]. Hydrogen, with its high energy density (143 kJ/g), has been proposed as a promising candidate to replace fossil fuels in the future due to the fact that the only combustion product is water, which is environmentally friendly [5][6][7].…”

“…Therefore, activating the inert edge sites is an efficient way to enhance its electrocatalytic activity. 2 …”

Recent Overview of Solar Photocatalysis and Solar Photo-Fenton Processes for Wastewater Treatment

“…Mineralization of organic compounds (conversion to CO 2 and mineral acids) by the TiO 2 solar photocatalytic process depends directly on the synthesis method of the catalyst [121][122][123][124][125][126], type of doping materials [11,112,113,[117][118][119][120], annealing temperature [127][128][129][130][131], catalyst load [132][133][134][135], pollutant concentration [136][137][138][139], and pH of the aqueous solution [140][141][142]. There are other parameters like reaction temperature, reactor configuration (geometry), reactor material, air sparging in the reactor solution, and the solar radiation intensity (solar concentration ratio) [143] that are important too in the TiO 2 solar photocatalytic process.…”

“…Introduction of such energy levels in the band gap induces the red shift in the band gap transition and the visible light absorption through a charge transfer between a dopant and conduction band (or valence band) [112]. Nevertheless, these changes depend on the nature of dopants, synthesis methods, annealing process, dopant concentration, and dopant distribution [11,112,113,[117][118][119][120].…”

Plasmon Mediated Photocatalysis by Solar Active Ag/ZnO Nanostructures: Degradation of Organic Pollutants in Aqueous Conditions

“…Zinc Nitrate 30.00g is added to 0.5% starch solution [11] and the mixture was kept under constant stirring for an hour. After complete dissolution of the zinc nitrate, temperature was increased to 60 °C and 600 ml NaOH solution in water (0.2 M) was added to the reaction mixture.…”