Hierarchical photocatalysts

Abstract

As a green and sustainable technology, semiconductor-based heterogeneous photocatalysis has received much attention in the last few decades because it has potential to solve both energy and environmental problems. To achieve efficient photocatalysts, various hierarchical semiconductors have been designed and fabricated at the micro/nanometer scale in recent years. This review presents a critical appraisal of fabrication methods, growth mechanisms and applications of advanced hierarchical photocatalysts. Especially, the different synthesis strategies such as two-step templating, in situ template-sacrificial dissolution, self-templating method, in situ template-free assembly, chemically induced self-transformation and post-synthesis treatment are highlighted. Finally, some important applications including photocatalytic degradation of pollutants, photocatalytic H2 production and photocatalytic CO2 reduction are reviewed. A thorough assessment of the progress made in photocatalysis may open new opportunities in designing highly effective hierarchical photocatalysts for advanced applications ranging from thermal catalysis, separation and purification processes to solar cells.

Kinetic study on adsorption of Cr(VI), Ni(II), Cd(II) and Pb(II) ions from aqueous solutions using activated carbon prepared from Cucumis melo peel

“…Adsorption is a simple treatment method for removing metal ions in wastewater, and activated carbon is a powerful adsorbent that is commonly used in industrial wastewater treatment plant (Saleh and Gupta 2011;Saleh and Gupta 2012a, b;Karthikeyan et al 2012;Mittal et al 2009aMittal et al , b, 2010Mittal et al , 2012Wang et al 2006Wang et al , 2009. The growing interest in this material is motivated by its favorable surface properties, uniformity of adsorption, and consequently exceptional adsorption effect (Zuorro and Roberto 2010;Saleh and Gupta 2012b;Saleh and Gupta 2014a, b;Li et al 2016;Devaraj et al 2016). A wide variety of materials have been investigated for this purpose and they can be classified into three categories: (1) natural materials, (2) agricultural wastes, (3) industrial wastes (Saravanan et al 2013a(Saravanan et al , b, c, d, e, f, 2014a(Saravanan et al , b, c, 2015aRajendran et al 2016;Huang et al 2015).…”

Pyrene-Based Conjugated Polymer/Bi2MoO6 Z-Scheme Hybrids: Facile Construction and Sustainable Enhanced Photocatalytic Performance in Ciprofloxacin and Cr(VI) Removal under Visible Light Irradiation

“…As a trustworthy technique to harvest solar light for environmental remediation, photocatalysis has been widely utilized in the removal of antibiotics and heavy metals by virtue of its sustainable, economical, and environmentally benign properties [1][2][3][4]. To acquire suitable photocatalysts with broad photo absorption, fast charge transportation, and efficient surface reactions, several commonly used techniques have been explored, such as sensitization, doping, fabrication of heterojunction, surface engineering, and so on [5][6][7][8][9].…”

A Review on the Fabrication of Hierarchical ZnO Nanostructures for Photocatalysis Application

“…However, only a small part mentioned the synthesis of hierarchical ZnO materials in photocatalytic application [4,[8][9][10]. In addition, especially in the photocatalytic application of ZnO, most of the previous reviews are limited to low dimension (0D, 1D and 2D) ZnO nanostructures, where reviews about hierarchical ZnO nanostructures are still insufficient.…”

“…In recent years, many researchers have focused on the fabrication of hierarchical semiconductor nanostructures and nanocomposites owing to their advantages, including high surface area, porous structures, as well as enhanced light harvesting, etc. [4]. Particularly, zinc oxide (ZnO) has attracted considerable attention as an efficient and promising candidate in photocatalytic applications because of its low cost, non-toxicity and high quantum yields [5][6][7].…”