General Review on the Components and Parameters of Photoelectrochemical System for CO₂ Reduction with in Situ Analysis

Abstract

One of the promising renewable energy sources is converting CO2 into useful chemical fuels; it will help to overcome both energy supply and global warming issues. Among various methods for CO2 reduction, photoelectrochemical (PEC) CO2 conversion is the most promising and easy method so far because it can be useful to control thermodynamics and kinetics of CO2 reduction reaction for product selectivity and fast reaction kinetics by mimicking natural photosynthesis without high input energy cost. However, it has some limitation factors that create difficulties for widespread utilization. The detection of CO2 products and intermediates on a small scale is another challenging part in this field. The small amount of the CO2 product can be further oxidized or evaporated, which could be difficult to be detected. Therefore, an in situ technique is a good approach to study the proper reduction mechanism during the CO2 reduction process. This review starts with basic concept of solar to fuel (STF) conversion by CO2 reduction and covers various aspects related to photoelectrochemical CO2 reduction. This main theme is completely depending on important parameters such as photoanode materials, photocathode materials, electrolyte solutions for photoelectrochemical CO2 reduction with the most important in situ measurement techniques for product analysis.

Solar‐powered chemistry: Engineering low‐dimensional carbon nitride‐based nanostructures for selective CO2 conversion to C1C2 products

“…An n‐type semiconductor is used as a photoanode, whereas a p‐type semiconductor is used as a photocathode. Light irradiation induces the formation of electron–hole pairs at the photoanode (photocathode), where the electrons (holes) will travel to the cathode (anode) to carry out the reduction (oxidation) reaction while the inverse occurs on the surface of the photoelectrode 318 . The use of PEC for CO 2 RR can reduce the electrical bias and overpotential compared to the electrochemical CO 2 RR.…”

Band Positioning in Boron Nitride and Metal-Free Photocatalysts via Photoelectron- and UV-Vis Diffuse Reflectance Spectroscopy

“…67 In doing so, we can align the known redox potentials for CO2/CO (-0.11 V) and H + /H2 (0.00 V) reported in the literature on the absolute energy scale. 68 The redox potential for CO2/CO is that measured at 298 K in water as per the work of Bratsch. 69 It is commonly used for the study of both aqueous and gaseous systems as the value for the gaseous system is not available.…”

Synthesis, Characterization and Visible-Light Photocatalytic Activity of Solid and TiO2-Supported Uranium Oxycompounds

“…Semiconductor photocatalysis has the potential for efficient utilization of light energy reaching the Earth from the Sun [1]. Commonly, semiconducting materials can be used for utilization of solar radiation via a number of routes: (i) to convert the energy of light directly into electricity by the photovoltaic effect using various silicon, cadmium telluride, copper indium gallium selenide, dye-sensitized (also well-known as Grätzel cells), perovskite, and other solar cells [2,3]; (ii) to store the energy in a form of chemical bond energy in fuels via photocatalytic or photoelectrochemical hydrogen evolution [4][5][6][7] and reduction of carbon dioxide [8][9][10]; (iii) to carry out useful chemical reactions, for instance, to synthesize highvalue products via partial selective photocatalytic or photoelectrochemical oxidation [11,12] and to purify water or air via photocatalytic degradation and complete oxidation of pollutants [13,14]. Therefore, the photocatalytic processes can solve both energy and environmental issues.…”