Synthesis of large surface area nano-sized BiVO4 by an EDTA-modified hydrothermal process and its enhanced visible photocatalytic activity

Nonaqueous Synthesis of a Bismuth Vanadate Photocatalyst By Using Microwave Heating: Photooxidation versus Photosensitized Decomposition in Visible‐Light‐Driven Photocatalysis

“…Ahigherdegree of crystallinity might be achieved by increased oxidation temperatures, but to minimise sintering processes, the oxidation temperature was chosen to be as low as requiredt or emove the organic components. The N 2 physisorption experiments for the as-prepared BiVO 4 catalysts gave BET surface areas of 7-16 m 2 g À1 (Table 1), which is in accordance with the surfacea reas of nanosized BiVO 4 ,f or example, reported by Sun et al [18] (10 m 2 g…”

“…[12,13] It crystallises in three different polymorphs, az ircon structure with tetragonal symmetry and scheelite structure with either monoclinic or tetragonal symmetry.A mong these, monoclinic scheelite-type BiVO 4 exhibits af avorable visible-light response and activity. [14,15] With af ocuso nc atalyst performance various synthetic routes have been reported for monoclinic BiVO 4 ,w hich include solid-state reaction, [16] hydrothermalp reparation, [17][18][19] sonochemical methods, [20] metal-organic decomposition [21] , and methods based on co-precipitation. [22] In addition, microwave-assisted hydrothermal synthesis was used to prepare nanostructured monoclinic BiVO 4 .…”

Hydrothermal preparation of BiVO4 photocatalyst with perforated hollow morphology and its performance on methylene blue degradation

“…When EDTA was added into the solution, it would react with Bi 3 þ to form chelate compound of (Bi 3 þ -EDTA) [24]:…”

“…Therefore, VO 3 À had less opportunity to come across the free Bi 3 þ to form BiVO 4 . When (Bi 3 þ À EDTA) gradually dissociated and released Bi 3 þ , the combination of Bi 3 þ and VO 3 À could be facilitated [24]:…”

“…When EDTA was added into the solution, the chelate compound of (Bi 3 þ À EDTA) decreased the concentration of free Bi 3 þ in the solution [18,24]. The concentration of EDTA or free Bi 3 þ became the control factor to the growth of BiVO 4 crystal in different directions.…”