Qing Cen,Qiaoyuan Gao,Chenlu Zhang,Yingqi Liu,Qi Wang,Qi Wang
In this study, visible-light-active iron tungstosilicate (FeSiW) was fabricated via solvothermal method . Fe 3+ was applied as counter ion to precipitate with silicotungstic acid (H 4 SiW 12 O 40 ) in methanol solution. It can be observed from FT-IR spectra that the Keggin structure of SiW 12 O 40 4− was well maintained in FeSiW. Besides, the effect of different initial molar ratios of Fe 3+ to H 4 SiW 12 O 40 was investigated (from 4:1 to 4:4). By photoelectrochemical characterizations, such as photocurrent response and Mott-Schottky (M-S) plots, easiest generation of electron-hole pairs and lowest charge transfer resistance can be observed on FeSiW with initial molar ratio of 4:3. Moreover, FeSiW with 4:3 ratio also displayed highest activity for photocatalytic reduction of Cr(VI), despite of the largest band gap (ca. 2.71 eV). The lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) of the optimized FeSiW were estimated to be +0.03 V and 2.74 V vs NHE, respectively, which were thermodynamically feasible for Cr(VI) reduction and H 2 O oxidation . Even under acidic condition (pH 3), the optimized photocatalyst displayed good stability in cyclic runs. Therefore, the present study opens a new way for heterogeneous polyoxometalates as efficient photocatalyst for environmental application.
A reusable, underwater adhesive, self-healing, and conductive hydrogel was developed by the construction of an interpenetrating network structure consisting of a tungstosilicic acid (SiW) cross-linked hydroxypropyl methylcellulose (HPMC) network and a ferric ion cross-linked poly(dimethylaminoethyl methacrylate) (PDMAEMA) network. The impacts of HPMC, SiW, DMAEMA, and ferric chloride content on adhesion properties were carefully evaluated. The results demonstrated that the 3–2–0.5–60 hydrogel showed the optimal shear adhesion strength. The obtained HPMC/SiW-PDMAEMA/Fe3+ hydrogels exhibited reusable adhesion on the surfaces of various materials such as glass, wood, metals, agate, plastics, ceramics, and rubber. It was noticed that the HPMC/SiW-PDMAEMA/Fe3+ hydrogels also displayed attractive underwater adhesion performance, and they could be adhered to various substrates underwater without any pretreatment or long curing time. In addition, the HPMC/SiW-PDMAEMA/Fe3+ hydrogel showed strain-responsive conductivity and outstanding self-healing performance. Therefore, this work developed a simple method to fabricate reusable, underwater adhesive, conductive, and self-healing hydrogels, which ensure the hydrogel’s broad applicability.
危险品化学品经营许可证（带存储）