Small Nanosized Oxygen-Deficient Tungsten Oxide Particles: Mechanistic Investigation with Controlled Plasma Generation in Water for Their Preparation

Abstract

Production of oxygen-deficient tungsten oxide nanoparticles with a diameter of around 10 nm have been successfully developed using a microwave-induced plasma in liquid technique. The prepared blue-green nanoparticles exhibit strong absorption in the visible region; thus, these could be efficient visible-light photocatalysts. The high-angle annular dark-field images revealed the dislocation of tungsten, which causes oxygen deficiencies.

Coupling the Surface Plasmon Resonance of WO3–x and Au for Enhancing the Photocatalytic Activity of the Nonoxidative Methane Coupling Reaction

“…After that, a small tail that extends to the NIR range is observed, which indicates that a few oxygen vacancies are presented. This point agrees with the previous literature on nanoscale WO 3 material, that instinct oxygen vacancies are always there . The band gap was calculated from the Tauc plot shown in Figure S2, and the corresponding value was 2.69 eV, close to the reported data of WO 3 nanocrystalline with a mean size of 45 nm .…”

“…This point agrees with the previous literature on nanoscale WO 3 material, that instinct oxygen vacancies are always there. 35 The band gap was calculated from the Tauc plot shown in Figure S2, and the corresponding value was 2.69 eV, close to the reported data of WO 3 nanocrystalline with a mean size of 45 nm. 36 For the 1Au-WO 3 composite, while the absorption below 400 nm is similar to that of WO 3 , a distinct peak at ∼591 nm is shown, and the color of the sample becomes dark purple.…”

Characterization of the Efficiency of Photo-Catalytic Ultrafiltation PES Membrane Modified with Tungsten Oxide in the Removal of Tinzaparin Sodium

“…Among these extraordinary photocatalytic nanomaterials are those made of WO 3 , which reported a stupendous performance as photocatalysts, gas sensors, and electrochromic devices. WO x x ≤3 nanomaterials have gained considerable attention as a result of their abundance, high oxidation ability, and chemical stability at suitable pH values [29,30]. They are n-type semiconductors with band-gap energy between 2.4-3.0 eV [31,32].…”

“…WO 3 is also recognized for its nonstoichiometric properties, as the lattice can hold a considerable number of oxygen vacancies (WO 3 , WO 2.9 , WO 2.8 , WO 2.72 , and WO 2 ). Since photocatalytic activity is fundamentally influenced by the recombination rate of the photo-generated electrons and holes, many attempts have been made to minimize such limitations and enhance the separation and migration of these photo-generated holes and electrons [29,30,33,34]. Mohd Hir et al (2017) [35] immobilized photocatalytic nanoparticles (ZnO) into a PES matrix.…”

Solution Plasma-Synthesized Black TiO2 Nanoparticles for Solar–Thermal Water Evaporation

“…No need for complicated operations, plasma electrolysis in a solution with a metal electrode as the raw material was used in nanomaterial synthesis of metals, semimetals, and metal oxides, which was also named as the solution plasma process (SPP). − The nanomaterial formation in these synthetic systems was based on a melting/evaporation-quenching mechanism, in which the concentrated current flow sharply increased the local temperature of current spots on the electrode by Joule heating, thus resulting in the local melting of the metal electrode. The molten electrode fraction was quenched in the liquid phase and transformed into the target nano-/microparticles. , The SPP method has been applied for the synthesis and activation of TiO 2 nanoparticles.…”