Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

Abstract

A new type of photocatalyst is proposed on the basis of aero-β-Ga2O3, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga2O3 material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga2O3 functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga2O3 with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga2O3 with noble metals are discussed to elucidate their potential for environmental applications.

Synthesis and Nanostructure Investigation of Hybrid β‐Ga2O3/ZnGa2O4 Nanocomposite Networks with Narrow‐Band Green Luminescence and High Initial Electrochemical Capacity

“…[23] In this study, the aero-GaN(ZnO) networks are converted into hybrid aero-β-Ga 2 O 3 /ZnGa 2 O 4 nanocomposites via an interfacial solid-state reaction by annealing under atmospheric conditions for about 60 min at T = 950 °C and T = 1100 °C (Figure 1c). [27,28]…”

“…[27] Further, their modifications by functionalization with metallic nanoparticles during and after the synthesis have been demonstrated to improve the catalytic performance. [28,29] A wide range of possible applications becomes possible from microfluidics and pneumatic systems [18] to optical light diffusion [24] or photocatalysis [28,29] and can be extended to bio-scaffolds and hydrogel templates as well as supercapacitor structures. [30] This heterogeneity in the material selection and associated properties is driving fundamental research to identify fabrication routes and new applications of new ultralight weight and porous aero-networks.…”

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods

“…Among porous semiconductor materials, recently developed super-lightweight ones with ultrahigh degree of porosity, the so-called aeromaterials, are of special interest [11][12][13][14][15][16][17][18]. Aeromaterials are similar to aerogels, which are widely explored and used in various applications.…”

“…Sacrificial porous ZnO networks of microtetrapods have also been used for the preparation of the abovementioned semiconductor-based aeromaterials. Most of these aeromaterials have been produced by hydride vapor phase epitaxy (HVPE) [11][12][13][14][15][16][17][18]. Particularly, an aero-ZnS material exhibiting hydrophilic properties under tension and hydrophobic properties when compressed against water was fabricated using HVPE of CdS on sacrificial ZnO microtetrapods through the simultaneous or subsequent transformation of CdS into ZnS and the removal of the sacrificial ZnO crystals [16].…”

Self-Propelled Aero-GaN Based Liquid Marbles Exhibiting Pulsed Rotation on the Water Surface

“…Over the last years, we developed wide-band-gap-semiconductor-compound-based aero-materials consisting of hollow microtetrapods, which prove to be promising for a variety of applications [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Furthermore, we demonstrated self-propelled, asymmetrically shaped aero-GaN and aero-ZnS based liquid marbles with the liquid droplet composed of alcoholic solution [ 13 , 14 ].…”