Synthesis of WO3 nanorods through anodization in the presence of citric acid: Formation mechanism, properties and photoelectrocatalytic performance

Hydrated Orthorhombic/Hexagonal Mixed-Phase WO3 Core–Shell Nanoribbons for Hole-Mediated Photocatalysis

“…The slope obtained from the linear fitting of C –2 vs V plot (Figure b) gives the value equal to 2/ q εε 0 N D . Thus, N D = 2/( q εε 0 × slope), with q = 1.602 × 10 –19 C, ε 0 = 8.8541 × 10 –14 F cm –1 , and ε ∼ 50 . The values of slope obtained were 3.32 × 10 11 cm 4 F –2 V –1 for W120 and 4.71 × 10 11 cm 4 F –2 V –1 for W500.…”

“…The slope of both W120 and W500 were found to be positive, which implies that they exhibit n-type semiconductor characteristics with electrons as the major charge carriers. For an n-type semiconductor, the Mott–Schottky relation is given as where C , q , ε, ε 0 , and N D denote the total capacitance, charge of an electron, semiconductor dielectric constant, free space permittivity, and donor density, respectively. E applied and E FB are the applied and flat band potentials, k is the Boltzmann constant (1.38 × 10 –23 JK –1 ), and T is the room temperature (298 K) at which the measurements are carried out.…”

“…Thus, N D = 2/(qεε 0 × slope), with q = 1.602 × 10 −19 C, ε 0 = 8.8541 × 10 −14 F cm −1 , and ε ∼ 50. 44 The values of slope obtained were 3.32 × 10 11 cm 4 F −2 V −1 for W120 and 4.71 × 10 11 cm 4 F −2 V −1 for W500. Thus, N D was calculated as 8.49 × 10 18 and 6.0 × 10 18 cm −3 for W120 and W500, respectively.…”

“…The slope of both W120 and W500 were found to be positive, which implies that they exhibit n-type semiconductor characteristics with electrons as the major charge carriers. For an n-type semiconductor, the Mott−Schottky relation is given as 44…”

Incorporation of Ions into Nanostructured Anodic Oxides—Mechanism and Functionalities

“…Nanostructured anodic zirconia is also utilized as a photocatalyst [34] or as a substrate for Surface Enhanced Raman Spectroscopy (SERS) [35]. Additionally, other metals, like Hf [36], Mo [37], Nb [38], Sn [39], Ta [40], W [41,42], Zn [43,44], gain much attention as starting materials for anodizing.…”