Influence of substituted acetic acids on “bridge” synthesis of highly photocatalytic active heterophase TiO2 in hydrogen production

Enhancing Photocatalytic Properties of TiO2 Photocatalyst and Heterojunctions: A Comprehensive Review of the Impact of Biphasic Systems in Aerogels and Xerogels Synthesis, Methods, and Mechanisms for Environmental Applications

“…In hydrothermal conditions, water adsorbs on amorphous titania, modifying [TiO6] octahedron to its crystallization [8,78]. The investigations proposed using temperatures of 40 and 50 °C [79], 80 °C [19,80,81]; and, 60 °C and 90 °C [82] to obtain different TiO2 heterojunctions.…”

“…Fluorine doping in TiO 2 inhibits the anatase-to-rutile phase transformation, ensuring a highly crystalline anatase structure even at 700 • C. Simultaneously, it fosters the creation of surface defects, contributing to enhanced photoactive absorption around 365 nm [112], with the effect intensifying at higher calcination temperatures [113]. Cihar et al introduced fluorine (F) and chlorine (Cl) ions by using substitutive acetic acids (SAAs) as precursors during hydrothermal sol-gel synthesis [19].…”

“…The superior efficiency of Cu-Pt/TiO 2 is ascribed to high electron density on the bimetallic particles (due to the interaction of Cu and Pt) when compared to the single metal (Cu or Pt) doped TiO 2 . The different morphologies and photocatalytic performance of TiO 2 composites or metal doping have already been studied, where between them, the most efficient catalyst was still Pt nanoparticles, producing about 181,770 mmol.h −1 .gr −1 [15,19,43,44,106,120]. Table 1 presented the advantages and limitations of different doping methods.…”

“…Photogenerated hydrogen is influenced by surface defects, including grain boundaries and interfacial interfaces, which serve as active centres for photocatalysis [17]. Additionally, the beneficial charge transfer between biphasic systems, such as anatase-rutile [18] and anatase-brookite [19], is noteworthy.…”

“…Strategies to extend TiO 2 s absorption into the visible range, such as bandgap engineering or coupling with narrow-bandgap semiconductors, are being pursued to enhance its photocatalytic activity under solar light [37]. Introducing co-catalysts like Pt or Pd onto TiO 2 surfaces improves charge transfer and enhances the efficiency of specific reactions [19,38]. Additionally, developing heterogeneous photocatalysis systems, including immobilizing TiO 2 on various supports or incorporating it into membranes, aims to improve catalyst recovery, reusability, and stability [39,40].…”