Oscillating electric-field effects on adsorbed-water at rutile- and anatase-TiO2 surfaces

Electric Field Effects on Photoelectrochemical Water Splitting: Perspectives and Outlook

The grand challenges in renewable energy lie in our ability to comprehend efficient energy conversion systems, together with dealing with the problem of intermittency via scalable energy storage systems. Relatively little progress has been made on this at grid scale and two overriding challenges still need to be addressed: (i) limiting damage to the environment and (ii) the question of environmentally friendly energy conversion. The present review focuses on a novel route for producing hydrogen, the ultimate clean fuel, from the Sun, and renewable energy source. Hydrogen can be produced by light-driven photoelectrochemical (PEC) water splitting, but it is very inefficient; rather, we focus here on how electric fields can be applied to metal oxide/water systems in tailoring the interplay with their intrinsic electric fields, and in how this can alter and boost PEC activity, drawing both on experiment and non-equilibrium molecular simulation.

The behaviour of water on the surface of kaolinite with an oscillating electric field

A quantitative understanding of oscillating electric field effects on the behaviour of water on the surface of kaolinite is vital for research in the field of clay-water systems. The behaviour of water molecules on the (0 0 1) and (0 0 -1) surfaces of kaolinite are systematically investigated in the absence or presence of an oscillating electric field using molecular dynamics simulations. The simulated results demonstrate that the applied oscillating electric fields parallel to kaolinite surface contribute to decreased amounts of adsorbed water molecules on the (0 0 1) surface of kaolinite. The oscillating electric field performs an inconspicuous effect on the adsorption of water on the (0 0 -1) surface of kaolinite. The behaviour of water on the surface of kaolinite will be impacted more severely by oscillating electric fields. Our results demonstrate that water molecules will rotate following the directions of the applied fields, which causes the decrease of hydrogen bonds, and thus, the weaker water-kaolinite interactions due to the applied field drive water molecules away from kaolinite surfaces. These results are of significance to understand the mechanisms of the oscillating electric fields affecting the behaviour of clay-water systems.