An unexplored role of the CrO_x shell in an elaborated Rh/CrO_x core–shell cocatalyst for photocatalytic water splitting: a selective electron transport pathway from semiconductors to core metals, boosting charge separation and H₂ evolution

Abstract

A core-shell structured Rh/CrOx cocatalyst has endowed various semiconductors with high efficiency in water splitting photocatalysis, where thin CrOx layers on Rh have been assumed to be physical blockers of...

Simultaneous Photodeposition of an Ag–Co Cocatalyst in Different pH Conditions To Improve the Activity of Calcium Titanate Photocatalyst for Carbon Dioxide Reduction with Water

“…The core–shell structure has long been often reported and they have an advantage to preventing side reactions for photocatalysts, such as Rh–Cr for water splitting and Ag–Cr for CO 2 reduction, where CrO x thin layer shell covered the surface of the core metal. In recent studies, the all-wrapped shell can function as a bridge between the core metal and photocatalyst surface to promote electron transfer in the case of Rh/CrO x for water splitting . In the present case, a hemisphere Ag NP was wrapped with the Co 3 O 4 floccule rather than a thin layer and the Co 3 O 4 floccule shell had a connection with the CTO surface (Figure i).…”

“…In recent studies, the all-wrapped shell can function as a bridge between the core metal and photocatalyst surface to promote electron transfer in the case of Rh/CrO x for water splitting. 21 In the present case, a hemisphere Ag NP was wrapped with the Co 3 O 4 floccule rather than a thin layer and the Co 3 O 4 floccule shell had a connection with the CTO surface (Figure 6i). Thus, the Co 3 O 4 floccule shell would function to prevent the side reactions or help the electron transfer from the CTO surface to the Ag NP.…”

Praseodymium Oxide Improving the Activity of a Silver-Loaded Calcium Titanate Photocatalyst for Carbon Dioxide Reduction with Water

“…Because the energy level of the conduction band minimum of CaTiO 3 (−0.8 eV) is more negative than that of Pr 6 O 11 (−0.64 eV), it is energetically possible for photoexcited electrons to transfer from the conduction band of the CTO particles to that of the Pr 6 O 11 surface layer. Because the Pr 6 O 11 layer has both Pr­(III) and Pr­(IV) cations, it can easily accept the electrons tentatively. , Recently, it was reported that a thin layer of CrO x in a well-known core–shell-structured Rh/CrO x cocatalyst can promote selective electron transfer from the semiconductor photocatalyst to the Rh metal cocatalyst while suppressing hole transfer, which supports the above-proposed electron-transfer ability of the Pr 6 O 11 layer because both cations, Pr and Cr, have possible multiple valence states. On the other hand, the Pr 6 O 11 moiety located on the oxidative facet of CTO had no acceleration for O 2 evolution (Table S4), which indicates that the Pr 6 O 11 layer has the same function as the CrO x layer to boost the electron-transfer selectively.…”

Recent advances in cocatalyst engineering for solar‐driven overall water splitting

“…Other favorable attributes of this process include control over the structure, composition, distribution, and oxidation state of the cocatalysts. Apart from (noble and transition) metals [44][45][46] and metal oxides [47][48][49], materials based on metal sulfides [50][51][52], metal (oxy)hydroxides [53][54][55], metal phosphates [56,57],…”