Light-Assisted Enhancement of Gas Sensing Property for Micro-Nanostructure Electronic Device: A Mini Review

In recent years, gas sensing electronic devices have always attracted wide attention in the field of environment, industry, aviation and others. In order to improve the gas sensing properties, many micro- and nano-fabrication technologies have been proposed and investigated to develop high-performance gas sensing devices. It is worth noting that light irradiation is an effective strategy to enhance gas sensitivity, shorten the response and recovery time, reduce operating temperature. In this review, firstly, the latest research advances of gas sensors based on different micro-nanostructure materials under UV light and visible light activation is introduced. Then, the gas sensing mechanism of light-assisted gas sensor is discussed in detail. Finally, this review describes the present application of gas sensors with improved properties under light activation assisted conditions and the perspective of their applications.

Effect of metal and non-metal doping on photocatalytic performance of titanium dioxide (TiO2): A Review

: Titanium dioxide (TiO2) is a known semiconducting material that has been effectively used in photo-catalytic processes to promote environmental sustainability. It can also reduce the environmental chaos caused by fossil fuel combustion to meet energy demands. Many studies have proposed modifications of the large band gap in TiO2, which causes visible light activation during photocatalytic reactions when exposed to UV light radiation. Therefore, many alterations such as the doping of nonmetals and metals to TiO2 have been investigated. In this review, we discuss advanced preparation techniques for TiO2 with various dopants and techniques. Characterization methods were performed to evaluate the structural, morphological, and optical properties of TiO2 doped with metal and nonmetal ions such as S, C, N, Fe, B, W, Ag, Nb, and Zn by various synthesis methods. We have also explored the experimental and other characteristics to determine the best doping component for use in real-time applications.

Light Activation of Nanocrystalline Metal Oxides for Gas Sensing: Principles, Achievements, Challenges

The review deals with issues related to the principle of operation of resistive semiconductor gas sensors and the use of light activation instead of thermal heating when detecting gases. Information on the photoelectric and optical properties of nanocrystalline oxides SnO2, ZnO, In2O3, and WO3, which are the most widely used sensitive materials for semiconductor gas sensors, is presented. The activation of the gas sensitivity of semiconductor materials by both UV and visible light is considered. When activated by UV light, the typical approaches for creating materials are (i) the use of individual metal oxides, (ii) chemical modification with nanoparticles of noble metals and their oxides, (iii) and the creation of nanocomposite materials based on metal oxides. In the case of visible light activation, the approaches used to enhance the photo- and gas sensitivity of wide-gap metal oxides are (i) doping; (ii) spectral sensitization using dyes, narrow-gap semiconductor particles, and quantum dots; and (iii) addition of plasmon nanoparticles. Next, approaches to the description of the mechanism of the sensor response of semiconductor sensors under the action of light are considered.

Practical room temperature formaldehyde sensing based on combination of visible-light activation and dipole modification

Implementing sensitive and fast ppb-level formaldehyde sensing at room temperature is still extremely demanded for practical indoor air quality monitoring. Herein, we developed a visible-light sensitive and dipole modified graphene-based...

Visible-light activation of peroxymonosulfate by NiCo2O4/Bi24O31Br10 to accelerate tetracycline degradation

Possible degradation mechanism with NiCo2O4/Bi24O31Br10 in a PMS/vis system.

Metal-free, regioselective, visible light activation of 4CzIPN for the arylation of 2H-indazole derivatives

Highly regioselective organo photocatalysis of 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) for the arylation of 2H-indazole is demonstrated.