Synthesis and Application of Innovative and Environmentally Friendly Photocatalysts: A Review

Abstract

Modern society faces two major challenges: removing pollutants from water and producing energy from renewable sources. To do this, science proposes innovative, low-cost, and environmentally friendly methods. The heterogeneous photocatalysis process fits perfectly in this scenario. In fact, with photocatalysis, it is possible both to mineralize contaminants that are not easily biodegradable and to produce hydrogen from the water splitting reaction or from the conversion of organic substances present in water. However, the main challenge in the field of heterogeneous photocatalysis is to produce low-cost and efficient photocatalysts active under visible light or sunlight. The objective of this review is to compare the new proposals for the synthesis of innovative photocatalysts that reflect the requirements of green chemistry, applied both in the removal of organic contaminants and in hydrogen production. From this comparison, we want to bring out the strengths and weaknesses of the proposals in the literature, but above all, new ideas to improve the efficiency of heterogeneous photocatalysis guaranteeing the principles of environmental and economic sustainability.

Mechanism of the Visible-Light-Promoted C(sp3)–H Oxidation via Uranyl Photocatalysis

“…A rotary evaporator (AnkeYqⓇ, N-1200B) with DL-400 was used for removing solvents. 1 H NMR spectra were collected on 400 MHz NMR spectrometers with a deuterated solvent (AVIII400 HD, Bruker, CDCl 3 = δ 7.26 for H). High-resolution mass spectrometry (HRMS) data were collected on an X500R.…”

“…Photocatalysis, which directly uses light as the energy source to realize molecular transformation, has shown great potential in petrochemical, pharmaceutical, perfumery, pesticide, and other fields. − Conventionally, a photosensitizer is needed for photoinduced reactions, among which metal complexes are one of the common types of visible light photocatalysts . There are many reports on transition metals and lanthanide photocatalysts (e.g., Ru, Ni, Ir, Au, Cu, Pd, La, Ce, Gd, Tb, Ho, Yb, and Lu), − while research on actinide photocatalysts is relatively rare and almost focuses on uranium .…”

Synthesis and Characterization of Hydroxyapatite/Titania Composite and its Application on Photocatalytic Degradation of Remazol Red B Textile Dye under UV Irradiation

“…A various techniques have been developed for removing pollutants and dyes from textile wastewater which include electrochemical oxidation (Latha et Among the available technologies, photocatalytic degradation is a promising method for the remediation of textile wastewater due to its high degradation efficiency, low toxicity, low maintenance, and environmentally friendly technology (Ren et al, 2021;Mancuso and Lervolino, 2022). Basically, photoexcitation of semiconductors by a photon energy with electrons are excited from the valence band to the conduction band when there is enough energy.…”

Robust Photocatalytic MICROSCAFS® with Interconnected Macropores for Sustainable Solar-Driven Water Purification

“…Water remediation is therefore one of the priorities in present-day scientific research. Among the explored methods for this purpose, heterogeneous photocatalysis offers many advantages, such as a low cost, high flexibility of the process, the use of natural energy sources, relatively low quantity of required catalyst, and, depending on the photocatalyst’s nature, high physical stability and recyclability of the materials employed, which make it an environmentally friendly technique [ 2 , 3 , 4 ]. However, the typical nanometric size of the photocatalysts, when used unsupported, in the powder form, makes their removal complex after the reaction, which is a significant drawback of this technique, being currently among the major limitations for the application of photocatalysis in a real-life scenario.…”