BiOX (X = Cl, Br, and I) Photocatalysts

Abstract

Photocatalysis technology has been wildly used to remove the most pollutants for environmental remediation under light irradiation. This chapter summarized the applications of BiOX (X = Cl, Br, and I) photocatalysts, including synthesis, photocatalytic performance without modification, enhanced VLD photocatalytic activity with the modification, and photocatalytic stability. Photocatalytic degradation (PCD) removal of volatile organic compounds (VOCs), contaminated chemicals, organic pollutants, and biological substances were introduced in this chapter. On the other hand, the morphologies, bismuth-rich effects, facet effects, and photocatalytic mechanisms of BiOX were discussed to provide effective methods for designing highly visible-light-driven (VLD) photocatalytic activity BiOX photocatalysts. The unsatisfactory points and future research directions also were briefly discussed at the end.

Nanostructured materials for photocatalysis

“…Additionally, it exhibits low recombination probability of photo induced electron-hole pairs due to its indirect band gap, thus resulting in a significantly improved photocatalytic activity. [244][245][246] Extensive reviews have been published on BiOX (X = Cl, BR, I) SCs, detailing their recent synthetic developments and photocatalytic applications: organic pollutants degradation, fuel production and removal of heavy metals. [247][248][249][250] Amongst BiOX (X = Cl, BR, I) SCs, BiOCl exhibits the highest photocatalytic activity under UV irradiation, with comparably higher activity to that of TiO2 for the degradation of dyes.…”

Resistive Mechanisms and Microscopic Electrical Models of Metal Oxide Resistive Memory

“…The equation for computing the bandgap of binary compound semiconductors can be expressed empirically as Equation ().where C = 43 is the empirical constant, V a and V c represent the valence electron number of the anionic and cationic atoms, respectively, and A a and A c represent the atomic number of the anionic and cationic elements, respectively. Table 2 shows the calculated and measured values of the bandgaps of some materials, [ 70,71 ] and as plotted in Figure , which shows that this rule has nice adaptability in most compound semiconductors, and transition metal oxides often exhibit excellent semiconductor characteristics. However, due to the presence of an unfilled d‐electron shell in transition metals, transition metal oxides like ZnO, CuO, and Cu 2 O exhibit significantly wide bandgaps.…”

“…If the formation energy of the lattice defects V M , X i (or V X , M i ) is lower than the energy released during this recombination process, it becomes more likely for the self‐compensation effect to occur. [ 70 ]…”

Single-Source Precursors for the Controlled Aqueous Synthesis of Bismuth Oxyhalides

“…Solar water splitting is a promising platform to generate hydrogen as a clean fuel. − Bismuth oxyhalides of the form BiOX (X = Cl, Br, I) are a special class of layered photocatalytic materials for this purpose. − The BiOX crystal structure comprises alternating positively charged Bi 2 O 2 2+ and negatively charged X – double layers. , This structure supports their use as photocatalysts, as a static internal electric field is generated between the layers that spatially separates photogenerated holes and electrons, providing a 2-dimensional path to the surface for these charge carriers to engage in redox reactions.…”