Saedy Saeed, Hiemstra Nico, Benz Dominik, Van Bui Hao, Nolan Michael, van Ommen J Ruud
Department of Chemical Engineering, Delft University of Technology Van der Maasweg 9 2629 HZ Delft The Netherlands
Faculty of Materials Science and Engineering, Phenikaa University Yen Nghia, Ha-Dong District Hanoi 12116 Vietnam.
Catal Sci Technol. 2022 Jun 8;12(14):4511-4523. doi: 10.1039/d2cy00400c. eCollection 2022 Jul 18.
The promotional effects on photocatalytic hydrogen production of Cu O clusters deposited using atomic layer deposition (ALD) on P25 TiO are presented. The structural and surface chemistry study of Cu O/TiO samples, along with first principles density functional theory simulations, reveal the strong interaction of ALD deposited Cu O with TiO, leading to the stabilization of Cu O clusters on the surface; it also demonstrated substantial reduction of Ti to Ti on the surface of Cu O/TiO samples after Cu O ALD. The Cu O/TiO photocatalysts showed remarkable improvement in hydrogen productivity, with 11 times greater hydrogen production for the optimum sample compared to unmodified P25. With the combination of the hydrogen production data and characterization of Cu O/TiO photocatalysts, we inferred that ALD deposited Cu O clusters have a dual promotional effect: increased charge carrier separation and improved light absorption, consistent with known copper promoted TiO photocatalysts and generation of a substantial amount of surface Ti which results in self-doping of TiO and improves its photo-activity for hydrogen production. The obtained data were also employed to modify the previously proposed expanding photocatalytic area and overlap model to describe the effect of cocatalyst size and weight loading on photocatalyst activity. Comparing the trend of surface Ti content increase and the photocatalytically promoted area, calculated with our model, suggests that the depletion zone formed around the heterojunction of Cu O-TiO is the main active area for hydrogen production, and the hydrogen productivity of the photocatalyst depends on the surface coverage by this active area. However, the overlap of these areas suppresses the activity of the photocatalyst.
本文介绍了通过原子层沉积（ALD）在P25 TiO₂上沉积Cu₂O团簇对光催化产氢的促进作用。对Cu₂O/TiO₂样品的结构和表面化学研究以及第一性原理密度泛函理论模拟表明，ALD沉积的Cu₂O与TiO₂之间存在强相互作用，导致Cu₂O团簇在表面稳定；同时还表明，在进行Cu₂O的ALD沉积后，Cu₂O/TiO₂样品表面的Ti⁴⁺大量还原为Ti³⁺。Cu₂O/TiO₂光催化剂的产氢性能有显著提高，最佳样品的产氢量比未改性的P25高11倍。结合产氢数据和Cu₂O/TiO₂光催化剂的表征，我们推断ALD沉积的Cu₂O团簇具有双重促进作用：增加电荷载流子分离和改善光吸收，这与已知的铜促进TiO₂光催化剂以及大量表面Ti³⁺的产生相一致，后者导致TiO₂的自掺杂并提高其产氢光活性。所得数据还用于修正先前提出的扩展光催化面积和重叠模型，以描述助催化剂尺寸和负载量对光催化剂活性的影响。比较用我们的模型计算得到的表面Ti含量增加趋势和光催化促进面积，表明Cu₂O - TiO₂异质结周围形成的耗尽区是产氢的主要活性区域，光催化剂的产氢性能取决于该活性区域的表面覆盖率。然而，这些区域的重叠会抑制光催化剂的活性。
