Oxidative photo-deposition of chromia: tuning the activity for overall water splitting of the Rh/CrO_xco-catalyst system

Abstract

By employing an oxidative photodeposition of CrOx the Rh/CrOx co-catalyst system was prepared on Ga2O3 and Ta2O5 resulting in up to 25% higher overall water splitting activities.

Anatomy of a Visible Light Activated Photocatalyst for Water Splitting

“…It cannot be ruled out that Zn also plays a role in the oxidation of H 2 O to O 2 since the valence band also consists of Zn. It has been claimed in the literature that CrO x sites can also play a role in the oxidation of H 2 O to O 2 on various oxide supports (Ba 5 Ta 4 O 15 , Ta 2 O 5 , and Ga 2 O 3 ), , however those photocatalyst reactions were operated under UV-irradiation and may not be applicable for our reaction conditions (visible light and oxynitride support). The addition of (Rh 2– y Cr y O 3 ) mixed oxide NPs and dispersed surface RhO x and CrO x sites will be able to trap the excited electrons that induce partially negative charges at Rh, Cr, and O atoms during photocatalysis which is observed.…”

“…It cannot be ruled out that Zn also plays a role in the oxidation of H 2 O to O 2 since the valence band also consists of Zn. It has been claimed in the literature that CrO x sites can also play a role in the oxidation of H 2 O to O 2 on various oxide supports (Ba 5 Ta 4 O 15 , Ta 2 O 5 , and Ga 2 O 3 ), 36,37 however those photo- The decay parameters displayed are those found in the PL spectra taken in the emission range of the peak value. 3 and 4).…”

Transition‐Metal‐Based Cocatalysts for Photocatalytic Water Splitting

“…Transition metal oxides involving the cobalt oxide, [ 48,355,356,358–361,363–365,381 ] manganese oxide, [ 49,366,381a,382 ] chromium oxide, [ 357,383 ] molybdenum oxide, [ 384 ] nickel oxide, [381a,382b] iron oxide, [ 362,381a ] copper oxide, [381a] lead oxide, [382b] and several bimetal oxides [ 367–370,385 ] have been investigated as active cocatalysts to collect photoinduced holes for O 2 production in photocatalytic water splitting. The deposition of these cocatalysts is usually achieved based on the impregnation, hydrothermal, and photodeposition methods.…”

“…In addition to the above oxides, the utilization of chromium oxide as an effective low‐cost oxidation cocatalyst was reported by Wark's group to improve overall water splitting performance. [ 357 ] Muhler and coworkers [ 383 ] showed that chromium oxide served as an active oxidation cocatalyst component to enhance photocatalytic activity and stability of Ga 2 O 3 in the entire water splitting process.…”

Synergistic effects of the Rh–S bond and spatially separated dual cocatalysts on photocatalytic overall water splitting activity of ZnIn2S4 nanosheets under visible light irradiation

“…Cocatalysts can serve as reaction sites and carrier trapping sites, which can be loaded on photocatalysts using simple methods (such as photodeposition and thermal deposition). 7,8 In general, noble metals (such as Pt, Rh, and Pd) 9–11 and metal oxides (such as IrO 2 , RuO 2 and Cr 2 O 3 ) 12–14 are used as cocatalysts for hydrogen evolution and oxygen evolution, respectively. Dual-cocatalyst loading can enhance carrier separation and reactant adsorption to achieve better photocatalytic activity, 15,16 for example, CdS loaded with NiS and carbon dots, 17 BiVO 4 loaded with Pt-Co 3 O 4 , 7 and BaTiO 3 loaded with Ag and MnO x .…”