Photocatalytic nanocomposite structured with boron

A boron integrated photocatalytic sol-gel nanocomposite having an enhanced optical recovery in the UV and visible region, comprising:

• (a) clusters of particles, each being composed of:
• (a.1) nanoparticles of at least one metaloxide;
• (a.2) particles (a.2.1), selected from the group consisting of boron, antimony, boron oxide, antimony oxide and mixtures thereof,
• and, optionally, particles (a.2.2), of at least one metalloidoxide different from boron and from antimony;
• (a.3) and a network (a.3) made of (i) organosiloxane(s) and/or (ii) silane(s)/silica and/or (iii) condensation products of silane(s) and metalalkoxides and/or metalloidalkoxides and/or alcohols;
• said network (a.3) encapsulating the particles (a.2.1) in such way that the possible hydrophilic character of particles (a.2.1) is confined inside the clusters and does not express outside;
• said network (a.3) including —O— bridges and optionally —C— bonds between the nanoparticles (a.1), said particles (a.2.1), and optionally the particles (a.2.2), of at least one metalloidoxide different from boron and from antimony;
• (b) at least one resin;
• said resin (b) being at least partially linked to particles (a) via —O— bridges and/or —C— bonds, and is covalently bonded to said network (a.3);
• (c) and optionally a liquid phase, wherein a part of the resin (b) is optionally dissolved,
• said nanocomposite having a surface morphology obtained after dip coating onto a standard surface according to standard protocol P1, and observed by Atomic Force Microscopy (AFM) according to a protocol P2, such that the coating has at least one of the following features (s1), (s2), (s3):
• (s1) the surface comprises a mean number of discrete peaks per μm2 between 5-65,
• (s2) the height of these peaks is between 5 and 100 nm,
• (s3) and the base diameter of these peaks is between 30 and 500 nm.