Photoelectrochemical Properties of BODIPY-Sensitized Anodic TiO₂ Layers Decorated with AuNPs for Enhanced Solar Performance

Abstract

An efficient hybrid photoanode based on the anodic TiO2 layer covered with gold nanoparticles (AuNPs) and BODIPY (boradiazaindacene) microrods for solar-driven water splitting experiments was developed. The BODIPY derivative (B-1) was synthesized, and their stability in different solvents was characterized in order to prepare the heterojunction photoelectrode. An insight into materials’ properties was gained by evaluating their morphology, optical, semiconducting, and photoelectrochemical performance. By combining the unique morphology of anodic TiO2 nanotubes with the electron trapping abilities of AuNPs and the light absorption properties of the BODIPY dye, a novel heterojunction photoanode generating 15 times higher photocurrent (∼120 μA cm–2) than pristine anodic TiO2 (∼8 μA cm–2) was obtained.

Surface Engineering of Anodic WO3 Layers by In Situ Doping for Light-Assisted Water Splitting

“…In this study, the observed relation is likely due to electron trapping in metal acting as an "electron sink". 73 This mechanism simultaneously extends the electron lifetime, 6,74 leading to efficient photocurrent generation very close to the absorption edge of the materials. The described effect is further corroborated by the electrochemical band gap values determined from the IPCE spectra.…”

“…Photoelectrochemical (PEC) water splitting under solar radiation is considered a promising strategy for producing hydrogen gas, which can serve as a highly energy-dense fuel with clean combustion byproducts . These systems rely on efficient and stable photoelectrodes, with the predominant focus in the field aimed at addressing low efficiency, limited long-term stability, and applicability restricted to the ultraviolet radiation region. − Anodic metal oxides show promise for this purpose due to their unique geometry, , relatively high surface area, and properties such as light absorption ability and generation of charge carriers under illumination . Furthermore, photoelectrodes based on anodic oxides do not require elaborate preparation because of the relatively good adhesion between the porous film and a conductive metal, as well as its perpendicular orientation to the substrate, which facilitates an efficient electron transfer path .…”

“… 14 However, its absorption abilities are still predominantly confined to the UV light region. Improvement of PEC properties of anodic oxide layers can be achieved through doping 15 and surface functionalization 16 (such as depositing cocatalyst, 17 other semiconductors, 18 , 19 polymers, 20 or dyes 6 ). In most cases, these modifications are implemented as post-treatment procedures (e.g., electrochemical deposition 19 ) followed by annealing 18 under precisely chosen conditions.…”

Exploring the photocatalytic and photodynamic effects of BODIPY-linked titanium dioxide nanoparticles

“…The functionalization of the TiO 2 surface with BODIPY molecules resulted in a slight decrease in the band gap of TiO 2 . This decrease was attributed to the low band gap energy of the BODIPY molecules [ 35 , 36 ].…”

BODIPY Chemisorbed on SnO2 and TiO2 Surfaces for Photoelectrochemical Applications

“…Successful binding requires the 3 and 5 positions of the molecule to be unsubstituted (Figure ). Since molecules of the BODIPY family have seen wide use as photosensitizers for solar fuels production, ,− we have now investigated the electron injection mechanism into different metal oxides by comparison of two BODIPY dyes, one of which is bound by the traditional carboxylic acid group and the other via the boron. The two dyes are ( T -4)-difluoro­[2-[phenyl­(2 H -pyrrol-2-ylidene-κ N )­methyl]-1 H -pyrrolato-κ N ]boron ( 1 ) and ( T -4)-difluoro­[4-[(5-methyl-1 H -pyrrol-2-yl-κ N )­(5-methyl-2 H -pyrrol-2-ylidene-κ N )­methyl]­benzoic acid]­boron ( 2 ), which contains the same 8-phenyl-dipyrrin backbone and BF 2 group of 1 .…”