Novel Ag 10 Si 4 O 13 /N–CeO 2 composite photocatalysts were synthesized by a facile one-pot method. XRD, SEM, EDS, and UV–Vis DRS were employed to characterize the structures of the samples. Moreover, the degradation activity of methyl violet (MV) was used to measure the photocatalytic performances of Ag 10 Si 4 O 13 , N–CeO 2 , and the Ag 10 Si 4 O 13 /N–CeO 2 composites. It was found that ASO-10 (the Ag 10 Si 4 O 13 /N–CeO 2 composite with 10 mg N–CeO 2 ) showed the highest photocatalytic activity in the degradation of MV, and the enhanced photocatalytic performance is attributed to an improvement in the separation efficiency of photoproduced electron–hole pairs. Effects of operational parameters, such as initial pH, catalyst dosage, initial dye concentration, anions and cations, have also been considered for better practical applications. In addition, the photocatalytic mechanism of the Ag 10 Si 4 O 13 /N–CeO 2 composites is also proposed.
Epoxy resin is a widely used thermosetting resin, but its application is limited due to its high brittleness and poor toughness after curing. In this study, we used repolymerized epoxy resin as the matrix and added carboxyl-terminated nitrile rubber (CTBN) and nano-cerium dioxide (n-CeO 2 ) to improve its impact strength without compromising its thermal properties. The test results show that with 15 wt.% CTBN, the tensile strength of the cured product is 60.59 MPa, the flexural strength is 132 MPa, and the impact strength is 22 KJ/m 2 , which are 206%, 200%, and 424% higher than those of pure epoxy resin, respectively. To further enhance the toughening effect, we introduced n-CeO 2 on the basis of 15 wt.% CTBN. The study found that with increasing n-CeO 2 content, the impact strength first increased and then decreased. When the n-CeO 2 content is 2 wt.%, the impact strength of the resin reaches 29.3 KJ/m 2 , which is 32% higher than that of CTBN. Additionally, thermogravimetric analysis (TGA) shows that the addition of n-CeO 2 significantly improves the thermal stability of CTBN/EP composites. Scanning electron microscopy (SEM) analysis reveals that CTBN cavitation occurs in the resin; n-CeO 2 plays a crucial role in particle debonding and crack pinning.
Graphical It's super ! The p-n junction was introduced to electrochemical catalysts for superoxide detection. Based on the superoxide dismutase mimic activity of CeO 2 and the high electrochemical catalytic activity of CuO, a non-enzymatic superoxide sensor was established. Owing to the construction of a p-n heterojunction, the sensing performances of p-CuO/n-CeO 2 composites were further enhanced. This method could serve as an effective strategy to overcome the intrinsic defects of semiconductor catalysts and improve their applications in electrochemical sensors. The performance of electrochemical sensors is mainly limited by the intrinsic properties of electrocatalysts fabricated on the electrode. Introducing a p-n heterojunction into semiconducing electrocatalysts is an effective strategy to enhance the sensing performance. In this paper, p-n-heterojunction-based CuO/CeO 2 nanocomposites were synthesized by a simple hydrothermal process, and the effect of different Cu/Ce molar ratios was explored. p-CuO/n-CeO 2 was found to exhibit higher conductivity and electrocatalytic activity toward the target superoxide anion (O 2 .− ) when compared to both bare CuO and CeO 2 . Characterization shows that different Cu/Ce ratios in p-CuO/n-CeO 2 materials result in a considerable variation in the Ce 3+ /Ce 4+ level, and energy band gap of CeO 2 , greatly affecting the electrochemical performance of p-CuO/n-CeO 2 . Under optimized conditions, these sensors exhibit high sensitivity and low detection limit toward O 2 .− . These results demonstrate that the performance of semiconductor-based electrochemical sensors may be enhanced by the electron-transfer process of p-n junction interfaces.