Thermo‐Photocatalysis: Environmental and Energy Applications

Abstract

Catalysis is an integral part of a majority of chemical operations focused on the generation of value‐added chemicals or fuels. Similarly, the extensive use of fossil‐derived fuels and chemicals has led to deterioration of the environment. Catalysis currently plays a key role in mitigating such effects. Thermal catalysis and photocatalysis are two well‐known catalytic approaches that were applied in both energy and environmental fields. Thermo‐photocatalysis can be understood as a synergistic effect of the two catalytic processes with key importance in the use of solar energy as thermal and light source. This Review provides an update on relevant contributions about thermo‐photocatalytic systems for environmental and energy applications. The reported activity data are compared with the conventional photocatalytic approach and the base of the photothermal effect is analyzed. Some of the systems based on the positive aspects of thermo‐ and photocatalysis could be the answer to the energy and environmental crisis when taking into account the outstanding results with regard to chemical efficiency and energy saving.

Mechanistic Considerations on the H2 Production by Methanol Thermal‐assisted Photocatalytic Reforming over Cu/TiO2 Catalyst

“…[9] In addition to the above strategy, mainly based on the development of efficient materials, there is a novel approach that considers the use of different energy sources. [10,11,12] It is well-known that the kinetics for the photocatalytic processes are usually insufficient for a high product yield. On the other side, thermal catalytic processes often suffer from a thermodynamic limitation for desired products at a low temperature.…”

When sonochemistry meets heterogeneous photocatalysis: designing a sonophotoreactor towards sustainable selective oxidation

“…3,[14][15][16][17] Highly photoactive materials are widely studied for application in environmental remediation in order to decompose/degrade hazardous compounds, but in most of the cases the outcome is complete and non-selective mineralization. 12,[17][18][19][20][21][22][23][24] The need for developing novel reactions for effective and selective valorization of organic compounds is in high demand, and two aspects can be assumed to be the most crucial: the development of a proper photoreactor and the use of a suitable photocatalyst for every specific photocatalytic reaction. Another strategy in order to elevate the photocatalytic reactions/transformations is to achieve process intensification by the application of alternative source of power.…”

Photocatalysis Enhanced by External Fields

“…[17] In general, microwave irradiation enhances the photocatalytic performance of semiconductors in two ways,n amely through thermal and nonthermal (specific) effects.The improvement in photocatalytic activity derived from the microwave thermal effect is similar to that in thermal catalytic processes:the increase in reaction temperature speeds up the surface redox reactions.M eanwhile,o wing to the thermal excitation and lattice thermal vibration of catalysts,the carrier concentration is increased. [18] However,m any studies have proposed that the remarkable enhancement of photocatalytic reaction dynamics stem not only from the thermal effect;t here are also large contributions from the non-thermal effect related to the surface properties of catalysts. [19] To investigate the microwave-specific effect, aphotoreactor was placed in amicrowave generator equipped with alight source and cooling system to maintain the ambient temperature (Figure 2a).…”