The enhanced photoreduction of Cr(VI) to Cr(III) using carbon dots coupled TiO2 mesocrystals

Polyaniline-TiO2 composite photocatalysts for light-driven hexavalent chromium ions reduction

“…Zhang and coauthors have done a lot of research on the synergistic effect of photocatalytic reduction of Cr(VI) and degradation of methyl orange [31], as well as the photoreduction of Cr(VI) and the synergistic oxidation of phenol [32,33]. According to the previous work, we found that the desorption of Cr(III) is also very important for the photocatalytic reduction of Cr(VI) [34][35][36]. The desorption of Cr(III) is beneficial to prevent the surface active sites of photocatalyst from being covered and inactivated.…”

“…MT was synthesized according to the procedures reported in Ref. [34]. Solution A was formed by dissolving 2.5 mmol of ammonium persulfate (APS) in 2 mL deionized water.…”

Cr(VI) remediation from aqueous environment through modified-TiO2-mediated photocatalytic reduction

“…The in situ formation of H 2 O 2 promotes the photoactivity to a great extent. Zhang et al synthesized CDs coupled with TiO 2 mesocrystals (CD/MT) in which the CDs acted as both the electron collectors and the active sites [144]. The negatively charged Cr(VI) species adsorbed effectively onto the positively charged surface of the CD/MT followed by photoreduction of Cr(VI) to Cr(III) ions that could be desorbed easily from the surface.…”

Construction of carbon quantum dots/single crystal TiO2 nanosheets with exposed {001} and {101} facets and their visible light driven catalytic activity

“…6,7 However, there are some strategies to make anatase TiO 2 active in the visible light region. Heteroelement structures such as doping, [8][9][10][11] p-n heterojunctions, 12,13 metal/semiconductor Schottky junctions 14,15 and dye sensitization [15][16][17] are proven to be effective ways to extend the absorption range into the visible light region. For example, N-doped TiO 2 creates a hybrid orbital above the VB of TiO 2 by imbedding an N atom into the lattice of TiO 2 (ref.…”

“…10) or C-doped TiO 2 can create a hybrid orbital above the VB of TiO 2 by replacing a lattice Ti atom or lattice O atom by C atoms. 11,18,19 They all successfully expand the catalyst's photoresponse to the visible light region with an enhanced visible light photocatalytic performance. 20 Nowadays homo-structures, including surface hetero facet junctions [21][22][23] and Ti 3+ self-doped black TiO 2Àx strategies, arouse great attention in the solar cell and pollution treatment elds.…”