Bi-Phasic photocatalytic particles prepared by sequential layer depositions for water cleaning and purification

Abstract

Bi-phasic photocatalyic particles have been prepared in the form of Janus-like structures (bi-phasic materials with two distinct properties on opposing sides of the particle) using a new synthetic procedure consisting of the sequential layer depositions of semiconductor oxide materials onto soluble substrates. A number of different systems have to date been investigated with an aim of photocatalytic applications. A general synthetic regime consists of utilising simple sol-gel chemistry to deposit sequential layers of photocatalytic material on top of a soluble substrate. The substrate can subsequently be removed yielding extremely fragile disks that fracture into bi-phasic powders of Janus like particles. These particles have two unique sets of properties contained in different faces of the same particle, aimed at the simultaneous reduction and oxidation of toxic species in water. This new synthetic technique is investigated for photocatalyic applications with an eye to efficient water purification, utilising the synergistic effect of the two materials to create highly effective photocatalysts. The photocatalytic activity of anatase/rutile (TiO 2 ) bi-phasic nanoparticle composites enhanced with platinum and deposited on the surface of polycarbonate filters has been successfully demonstrated. Deposition of the photocatalyst on filters overcomes expensive and time consuming recycling processes, adds porosity to the set up and reduces the scattering of nanoparticle dispersions.

Study of the Composition and Properties of Bivalve Mollusk Shells as Promising Bio-Indifferent Materials for Photocatalytic Applications (Example of Practical Use)

“…An alternative way of creating a photoactive layer is by matching carrier and precursor substances, in which, as a result of chemical interaction, the photocatalytically active coating is formed in one stage [38]. The most relative direction solving the problem of covering a carrier with a photocatalyst coating is the use of chemically complementary compounds of the carrier's material and the material of the initial components of photocatalysts [39]. The range of the reference literature data on the problems of using the elements of exoskeletons of marine and freshwater invertebrates as a bio-indifferent carrier of photocatalytic coatings is nondescript and yields little information, offering perspectives of scientific studies in this direction and justifying the novelty of the current research.…”