pH-regulated template-free assembly of Sb4O5Cl2 hollow microsphere crystallites with self-narrowed bandgap and optimized photocatalytic performance

Abstract

Sb4O5Cl2 hollow microspheres with self-narrowed bandgap and optimized photocatalytic performances are synthesized via a facile template-free method. It is found that the crystal structure and morphology of Sb4O5Cl2 crystallites are strongly dependent on the pH values of precursors. Nano-sized irregular-cuboids assembled Sb4O5Cl2 micro-particles and hollow microspheres can be synthesized at pH 1 and 2, whereas individual Sb4O5Cl2 micro-belts become to form when the pH is higher than 3. The irregular-cuboids assembled Sb4O5Cl2 micro-particles and hollow microspheres exhibit self-narrowed bandgap and higher light absorption ability compared with individual Sb4O5Cl2 micro-belts. The photoelectrochemical measurements show that the assembled Sb4O5Cl2 hollow microsphere crystallites prepared at pH 2 exhibit enhanced carrier density, improved separation efficiency of electron-hole pairs and decreased electron-transfer resistance. As a result, the irregular-cuboids assembled Sb4O5Cl2 hollow microspheres prepared at pH = 2 exhibit the highest photocatalytic activity for the degradation of gaseous iso-propanol (IPA) and Rhodamine B (RhB) aqueous solution. The good photocatalytic activity of Sb4O5Cl2 sample prepared at pH = 2 may be caused by the synergistic effect of its higher light absorption, the decreased electron-transfer resistance, the suppressed recombination of photogenerated electrons and holes, and the increased surface area.

Evaluation of 2-(salicylideneimino) thiophenol and other Schiff bases as bronze corrosion inhibitors by electrochemical techniques and surface analysis

“…13h) and Sb 3d (the last one not reported in Fig. 13) showed peaks at 486.7 eV (Sn3d 5/2 ), 138.5 eV (Pb4f 7/2 ) and 540.1 eV (Sb3d 3/2 ), respectively, indicating the presence of Sn(IV) [53][54][55][56][57], Sb(III) [61] and Pb) [58,59] oxides. As regards Pb, the binding energies of Pb oxides were too close to each other to allow for a precise attribution, but, on the basis of the E cor values of bronze in ARX10, the presence of Pb(II) (PbO-like) species was more likely [62].…”

pH-regulated hydrothermal synthesis and characterization of Sb4O5X2 (X = Br/Cl) and its use for the dye degradation of methyl orange both with and without light illumination

“…Furthermore, the solution is subjected to solar light illumination aer it attains adsorption-desorption equilibrium, and as a result, ROS get produced again and causes further dye degradation. 1,11,50 Although complete degradation is not possible, which could probably due to the formation of some by-products. The probable mechanism of dye degradation in both dark and light condition is proposed as follows:…”

pH-regulated antimony oxychloride nanoparticle formation on titanium oxide nanostructures: a photocatalytically active heterojunction

“…S8 and S9 †); their characteristics are unchanged except for a mild elevation of the baseline in the visible region. The corresponding band gaps were calculated from the Kubelka-Munk plots, 39 suggesting indirect band gaps in all composites (earlier in Sb 4 O 5 Cl 2 a direct band gap was suggested 16 ). Although the band gap in the anatase composites remains constant (3.26 eV), nanoparticle decoration in TiONT composites affects these values, as summarized in Table S1.…”

“…Data for certain Sb 4 O 5 Cl 2 compositions have only been published recently. 16 Therefore, Mott-Schottky analysis on our pH 1 composite (Sb 8 O 11 Cl 2 /TiONT) was performed, and the result is shown in Fig. S12.…”

“…Members of the antimony oxyhalide family [Sb x O y X z (X = Br, Cl, I)] went largely unnoticed as possible photocatalysts until now. Studies on photocatalytic Sb x O y Cl z structures (Sb 4 O 5 Cl 2 ) have been initiated very recently, 16 and to the best of our knowledge, only Sb 2 S 3 /Sb 4 19 and 20)) and in various morphologies in the past (microspheres, 16 nanorods, nanowires 20 etc. ), the synthesis of supported Sb x O y Cl z nanoparticles has not been reported yet.…”