Photocatalysis overall water splitting

Overall water splitting, anyway, was accomplished by a combined effect of sonolysis and photocatalysis. 

If a two-step mechanism, as shown in Eqs. (12.7) and (12.8), occurs, each product will be produced independently by alternating irradiation of ultrasound and light. An alternating irradiation was performed for overall water splitting under argon atmosphere. Ultrasonic wave must be irradiatea first followed by photoirradiation. This oraei of irradiation was decided from tbe scheme of sonophotocatalysis of water, as shown in Eqs. (12.7) and (12.8). As shown in Fig. 12.12, H2 and 02 were evolved by sonolysis and photocatalysis, respectively Thus each gaseous product was collected independently. 

The application of (oxy)nitrides in photocatalysis has been the subject of a number of recent reviews, for example, [10, 32]. In this area, the potential of materials for overall water splitting using visible light has been of particular interest. In this regard, Domen and coworkers have discussedthe behavior of d° and d ° electronic... 

Since the discovery of photoelectrochemical splitting of water on titanium dioxide (TiOj) electrodes (Fujishima and Honda, 1972), semiconductor-based photocatalysis has received much attention. Although TiO is superior to other semiconductors for many practical uses, two types of defects limit its photoeatalytic activity. Firstly, TiO has a high band-gap (E =3.2 eV), and it can be excited only by UV light (k < 387 nm), which is about 4-5% of the overall solar spectmm. Thus, this restricts the use of sunlight or visible light (Kormann et al., 1988). Secondly, the... 

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