Carbon-based heterogeneous photocatalysts for water cleaning technologies: a review

abstract

Clean and accessible water for all has been defined by the United Nations as a major goal to promote sustainability in a planet with improved life quality. However, the growth of population and global industry processes are having a massive impact on the water quality. The presence of organic pollutants in water and wastewater, such as pharmaceuticals, organic dyes and by-products of industrial processes, is a major issue. Conventional wastewater treatments are still limited, and, consequently, it is crucial to design innovative cleaning technologies such as heterogeneous photocatalysis with nanomaterials. Here we review mechanisms and applications of carbon-based nanostructures for heterogeneous photocatalysis applied to water purification. In particular, we present recent developments in synthetic routes and surface modification of carbon nanostructures aiming at their use under visible light irradiation. As such, carbon-based nanostructures decorated with distinct phases have been investigated, such as semiconductor compounds and polyoxometalates. The photocatalytic efficiency of hybrid nanocomposite materials is attributed to improved light harvesting and reduced recombination of photo-generated charge carriers. Furthermore, the recovery of photocatalysts by using assisted magnetic separation is presented as a promising strategy of reusability.

keywords

REDUCED GRAPHENE-OXIDE; ONE-POT SYNTHESIS; LIQUID-PHASE EXFOLIATION; HIGH-PERFORMANCE; QUANTUM DOTS; METHYLENE-BLUE; IN-VIVO; PHOTOLUMINESCENCE PROPERTIES; POLYOXOMETALATE CLUSTERS; SULFIDE NANOSTRUCTURES

subject category

Chemistry, Multidisciplinary; Engineering, Environmental; Environmental Sciences

authors

Lopes, JL; Martins, MJ; Nogueira, HIS; Estrada, AC; Trindade, T

Groups

G1 - Porous Materials and Nanosystems

Projects

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

Graphene-based semiconductor photocatalysis for a safe and sustainable water supply: an advanced technology for emerging pollutants removal (UTAP-ICDT/CTM-NAN/0025/2014)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

acknowledgements

J. L. Lopes and M. J. Martins thank FCT for doctoral Grants SFRH/BD/126241/2016 and SFRH/BD/131433/2017, respectively. A. C. Estrada acknowledges the costs resulting from the FCT hirings funded by national funds (OE), through UTAP-ICDT/CTM-NAN/0025/2014FCT - FundacAo para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. This research was funded through the FCT Project UTAP-ICDT/CTM-NAN/0025/2014, in the framework of the UT Austin-Portugal Program, and through the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.