Can Half-a-Monolayer of Pt Simulate Activity Like That of Bulk Pt? Solar Hydrogen Activity Demonstration with Quasi-artificial Leaf Device

Abstract

Pt is the best cocatalyst for hydrogen production. It is also well-known that the surface atomic layer is critical for catalysis. To minimize the Pt content as cocatalyst, herein we report on half-a-monolayer of Pt (0.5θ Pt ) decorated on earthabundant Ni−Cu cocatalyst, which is integrated with a quasiartificial leaf (QuAL) device (TiO 2 /ZnS/CdS) and demonstrated for efficient solar hydrogen production. For the QuAL, TiO 2 is sensitized with ZnS and CdS quantum dots by the SILAR method. The 0.5θ Pt -decorated Ni−Cu shows an onset potential of 0.05 V vs reversible hydrogen electrode for the hydrogen evolution reaction, which is almost similar to that of commercial Pt/C. Photoactivity of the present QuAL device with either bulk Pt or 0.5θ Pt -coated Ni−Cu cocatalyst is, surprisingly, equal. Our findings underscore that a fraction of a monolayer of Pt can enhance the activity of the cocatalyst, and it is worth exploring further for the high activity associated with atomic Pt and other noble metals.

Electronically Integrated Mesoporous Ag–TiO2 Nanocomposite Thin films for Efficient Solar Hydrogen Production in Direct Sunlight

“…The narrowing of bandgap in composite is due to Ag-TiO 2 Schottky junction and hence the Fermi level moves closer to the CB of TiO 2 NPs. [30,31] However, the E g is not an apparent function of the amount of Ag incorporated in the TiO 2 matrix, especially above 2% of Ag. [32] The different trend observed in our study may be due to a variety of reasons such as varying degree of Schottky junctions between Ag and TiO 2 , agglomeration of Ag nanoparticles and increase in particle size at higher Ag loading etc.…”

Stabilization of Orthorhombic CoSe2 by 2D-rGO/MWCNT Heterostructures for Efficient Hydrogen Evolution Reaction and Flexible Energy Storage Device Applications

“…Catalysts bear the responsibility of ensuring the active sites, reaction rate, and yield during the electrochemical reactions. Precious noble metals (Pt, Rh, and Ir) and their alloys (PtIrCo, PtCoRh, and PtRh) − /oxides (RhO 2 , IrO 2 ) are regarded as the most efficient electrocatalysts as they catalyze gaseous hydrogen formation at almost zero overpotential. Most importantly, the insufficiency and expensive Pt group members cause the practical utilization of HER to lag behind, predominantly hindering its large-scale commercialization.…”

Rationally Designed, Efficient, and Earth-Abundant Ni–Fe Cocatalysts for Solar Hydrogen Generation

“…In this context, it is worth noting a recent work by Bajpai et al on simulating the bulk Pt-cocatalyst activity, but with just half-amonolayer of Pt on NiCu cocatalyst. 21 First row transition metals, as earth-abundant cocatalysts, have been potentially explored for the solar H 2 evolution reaction. Among these, Cu, Ni, Fe, and Co (single or bimetal/alloy) based materials are found to be highly efficient toward the solar H 2 evolution.…”

“…Also, this strategy is highly beneficial from the economical point of view. In this context, it is worth noting a recent work by Bajpai et al on simulating the bulk Pt-cocatalyst activity, but with just half-a-monolayer of Pt on NiCu cocatalyst . First row transition metals, as earth-abundant cocatalysts, have been potentially explored for the solar H 2 evolution reaction.…”