A Beehive Inspired Hydrogen Photocatalytic Device Integrating a Carbo‐Benzene Triptych Material for Efficient Solar Photo‐Reduction of Seawater

Abstract

The dream to produce green, clean, and sustainable hydrogen from earth‐abundant and free resources such as seawater and sunlight is highly motivating because of the interest for desirable economical and societal applications in energy. However, it remains challenging to develop an efficient and unassisted photocatalytic device to split seawater molecules with just sunlight without any external bias. For the first time, a such novel hierarchical material has been developed, based on thin film technology that integrates TiO2 semiconductor layers, embedded gold nanoparticles, and a photosensitive carbo‐benzene layer. The design of the triptych device placing the photocatalyst in be‐to‐be increases the photoactive surface area by a factor 2. Its stability (>120 successive hours of hydrogen production and >5 days in a day/night representative alternation) and efficiency (Soler‐to‐Hydrogen 0.06%) are measured in NaCl‐salted water. The chloride ions act as hole scavengers and induce an increase of pH increasing in turn the sun‐driven hydrogen production rate.

On the UV–Visible Light Synergetic Mechanisms in Au/TiO2 Hybrid Model Nanostructures Achieving Photoreduction of Water

“…Therefore, a fixed thickness was kept for all samples to ensure the surface roughness and anatase/rutile phase ratio. A TiO 2 film of 270 nm was chosen as the reference for its highest hydrogen production as previously reported . As seen in the SEM images in Figure a, the TiO 2 thin film has a columnar morphology, which is rather disordered, with grain sizes from ∼20 to 50 nm, accompanied by the presence of porosities (∼1–10 nm) between the columns.…”

“…A TiO2 film of 270 nm was chosen as the reference for its highest hydrogen production as previously reported. 36 As seen in the SEM images in Figure 1a, the TiO2 thin film has a columnar morphology, which is rather disordered, with grain sizes from ~20 to 50 nm, accompanied by the presence of porosities (~1-10 nm) between the columns. This is in accordance with the morphology generally observed in TiO2 films deposited by vapor deposition.…”

Dominant role of OH− and Ti3+ defects on the electronic structure of TiO2 thin films for water splitting

“…The effect of the annealing temperature was analyzed by GI-XRD to investigate the changes of phase structure. Figure 1a 004), ( 112), ( 200), ( 105), ( 211), ( 204) and ( 215); (3,28) and at 2θ = 27.42, 54.37 and 68.93°, corresponding to the rutile planes (110), ( 211) and ( 301), (29,30) respectively. Both structures were confirmed with COD database, patterns number 1010942 and 9009083, for anatase and rutile, respectively.…”

High surface area TiO2 photocatalyst for H2 production through silicon micromachining

“…The WS mechanism takes place when photoexcited electrons and holes act as reducing and oxidizing agents to produce H 2 and O 2 , respectively (concept depicted in Figure 1) [6]. Since these seminal works, great progress has been made to understand the microscopic processes involved in photochemical systems and in catalyst engineering [7][8].…”