Morphologically and hierarchically controlled Ag/Ag2MoO4 microspheres for photocatalytic hydrogen generation

This paper describes the synthesis of a novel spherical-shaped Ag/Ag2MoO4 nanocomposite using phosphomolybdic acid as the initial reaction precursor in a single-step photoreduction process, as well as its application for water-splitting hydrogen production. The formation of interconnected Ag/Ag2MoO4 spheres with an average diameter of 1-2 mu m has been revealed by morphological details. The presence of metallic Ag on the surface of Ag2MoO4 with an average particle size of 0.5-1 nm was confirmed by the apparent resolution of transmission electron microscopic images and X-ray photoelectron spectroscopic details. The optical characterization suggested that metallic Ag NPs have an SPR effect. These Ag nanoparticles, when combined with phosphomolybdic acid, increased light absorptivity, resulting in a blueshift in the energy gap. The novel photochemical synthesis method resulted in the disorder-order structure and oxygen vacancies created during preparation for possible suppression of electron-hole recombinations. Under UV-Visible irradiation, the photocatalytic performance of the as-synthesized composite was tested for hydrogen production using ethanol as a sacrificial donor and Pt-as cocatalyst. Metallic Pt deposition on the surface of an Ag/Ag2MoO4 nanocomposite synergistically enhanced electron transport and accelerated proton reduction at an unprecedented rate. Despite the fact that the nanocomposite contains only 0.3% Pt0, the photocatalytic hydrogen production rate reached 0.4 mmol/h/g and remained stable at 0.63 mmol after four cycles of continuous catalytic process.. In 24 h of continuous reaction, total hydrogen evolution of 0.8 mmol was obtained by photocatalytic water splitting reaction with Pt0.3%/Ag/ Ag2MoO4 nanocomposite without ethanol replenishment. The manuscript represents a novel synthesis approach for the development of spherical Ag/Ag2MoO4 nanocomposite imparting significant contribution towards practical application PMA based composite for various photocatalytic applications.

Automated summary

This paper describes the synthesis of a novel spherical-shaped Ag/Ag2MoO4 nanocomposite using phosphomolybdic acid as the initial reaction precursor in a single-step photoreduction process, as well as its application for water-splitting hydrogen production. The synthesized nanocomposite exhibited excellent photocatalytic performance, achieving high hydrogen production rate under visible light. This study provides a new synthesis approach for visible light photocatalysts in practical applications.