Synergistic effect of p-type and n-type dopants in semiconductors for efficient electrocatalytic water splitting

Abstract

Co-substituting a stable material, e.g. TiO2, with both n- and p-type dopants, allows tuning its reactivity to activate the material for oxygen evolution. This opens up a new design avenue for acid water electrolysis electrocatalysts.

Modular CO2-to-CO Electrolysis Short-Stack Design─Impact of Temperature Gradients and Insights into Position-Dependent Cell Behavior

“…Outstanding efficiencies were demonstrated with membrane electrode assemblies (MEAs), where a gas diffusion electrode (GDE), functioning as the cathode, and a zero gap anode are directly mated on a polymer electrolyte membrane. − With the MEA, the distance between the electrodes is minimized to the thickness of the membrane, leading to a reduction of transport resistance and thus to an increase in energy efficiency. − High-performing flow cells, containing the MEA, operate with a single aqueous electrolyte or even only H 2 O at the anode. − Here, the oxygen evolution reaction (OER) takes place, oftentimes on an Ir-MMO catalyst surface which is a stable catalyst for the OER in various conditions. , The cathode provides a Ag catalyst layer, a highly selective and stable catalyst for the CO 2 -to-CO reaction, and is fed with humidified CO 2 gas from the rear side of the electrode. − , …”

“…13−15 Here, the oxygen evolution reaction (OER) takes place, oftentimes on an Ir-MMO catalyst surface which is a stable catalyst for the OER in various conditions. 3,16 The cathode provides a Ag catalyst layer, a highly selective and stable catalyst for the CO 2 -to-CO reaction, and is fed with humidified CO 2 gas from the rear side of the electrode. [13][14][15]17 Reportedly, the highest selectivities are reached with MEAs containing anion exchange membranes (AEMs).…”

Lattice oxygen evolution in rutile Ru(1−x)Ni(x)O2 electrocatalysts

“…The OER is confined to oxide-like surfaces, which often re-structure under operando conditions. Experimental development of oxygen evolving catalysts is done separately for acidic water electrolysis [2][3][4] and alkaline media electrolysis [5][6][7]. State of the art OER catalysts for acidic electrolysis are based on noble metal oxides such as RuO 2 and IrO 2 , the scarcity of which adversely affects large scale deployment of this technology.…”

“…The most common one, which is generally used as a foundation for the computational screening of prospective oxygen evolving catalysts conforms to a Volmer-Heyrovsky type of mechanism and can be described as a sequence of four consecutive concerted one electron/proton transfer reactions as outlined in eqs. (1)(2)(3)(4):…”

Surface electronic state modulation promotes photoinduced aggregation and oxidation of trace CO for lossless purification of H2 stream

“…To facilitate photoinduced •OH generation, we here modify the electronic states of TiO2 by doping it with magnesium, which has a smaller formal charge (+2 in MgO) compared to Ti (+4 in TiO2). Previous studies indicate that low-valence element doping can effectively weaken the binding strength of * O-containing species (such as * O and * OH) on the TiO2 surfaces [18,19]. Consequently, this may facilitate the •OH generation.…”