Advances in Hybrid Composites for Photocatalytic Applications: A Review

Abstract

Heterogeneous photocatalysts have garnered extensive attention as a sustainable way for environmental remediation and energy storage process. Water splitting, solar energy conversion, and pollutant degradation are examples of nowadays applications where semiconductor-based photocatalysts represent a potentially disruptive technology. The exploitation of solar radiation for photocatalysis could generate a strong impact by decreasing the energy demand and simultaneously mitigating the impact of anthropogenic pollutants. However, most of the actual photocatalysts work only on energy radiation in the Near-UV region (<400 nm), and the studies and development of new photocatalysts with high efficiency in the visible range of the spectrum are required. In this regard, hybrid organic/inorganic photocatalysts have emerged as highly potential materials to drastically improve visible photocatalytic efficiency. In this review, we will analyze the state-of-art and the developments of hybrid photocatalysts for energy storage and energy conversion process as well as their application in pollutant degradation and water treatments.

Multi-functional photocatalytic systems for solar fuel production

“…Carbon-based semiconductors and graphic carbon nitride (g-C 3 N 4 ) and graphene oxide systems have also been frequently used for photocatalytic production of H 2 O 2 from H 2 O and O 2 . 67,100–102 These heterogeneous materials may not be suitable to combine molecular catalysts to develop multi-catalytic functions. In contrast, the multi-catalytic functions of the COF and MOF can be further expanded because the COF and MOF have not only the intrinsic catalytic activity but also the capability to encapsulate additional catalytic sites.…”

Two viologen-functionalized pyrazolide-based metal–organic frameworks for efficient CO2photoreduction reaction

“…Furthermore, to evaluate their chemical stability, the two MOFs based on viologen-ligand were exposed to aqueous solutions with various pH levels. [1][2][3][4][5][6][7][8][9][10][11][12] Notably, Co-VOF demonstrated remarkable durability in saturated NaOH (aq.) (pH = 13), while in a strong acid solution of HCl (aq.)…”

“…5 Since then, several researchers have made numerous successful trials using a variety of photocatalysts and products including inorganic metal oxides (ZrO 2 , MgO, ZnO) and zeolites. 6 However, the application of these materials is limited owing to limitations, such as being active only in the ultraviolet region, which is equivalent to just 3% of the natural solar energy, and therefore their efficiency in CO 2 reduction is low. 7 Hitherto, a variety of active photocatalysts in the visible light region, including inorganic semiconductors, graphitic carbon nitride, homogeneous transition-metal complexes, covalent-organic framework materials (COFs), and metal-organic framework materials (MOFs) have been explored and their photocatalytic CO 2 reduction performance has been studied.…”

Molecularly Imprinted Methyl-Modified Hollow TiO2 Microspheres

“…The use of organically modified metal alkoxides has been described for the preparation of organically modified TiO 2 -based materials [ 6 ]. However, this has been a rarely used option, possibly owing to the inherent difficulty in understanding the chemistry of organically modified titania alkoxide precursors, which is much more exigent compared to ORMOSILs [ 7 ].…”

“…According to the authors, the presence of organic constituents in the inorganic matrix allowed for reconciliation of flexibility, porosity, and ability to host bioactive molecules, as well as their subsequent release. According to literature data, some organically modified titania alkoxides stand out as more stable and even less corrosive and ecotoxic than standard titania alkoxides [ 6 ]. These characteristics are the result of the special bond between the organofunctional group and the metal, which also interferes in the behavior of hydrolysis and consequent gelation of new compounds with hybrid characteristics [ 8 ].…”