Visible light-induced catalytic performance of composite photocatalyst synthesized with nanomaterials WO3 and two-dimensional ultrathin g-C3N4.

To improve the visible light-induced catalytic activities of Ultrathin g-C3N4 (UCN), a promising photocatalyst WO3/UCN (WU) was synthesized. Its visible light-driven photocatalysis performance was controllable by adjusting the theoretical mass ratio of WO3/UCN. We have calibrated the optimal preparation conditions to be: WO3/UCN ratio as 1:1, the stirring time of the UCN and sodium tungstate mixture as 9 h and the volume of concentrated hydrochloric acid as 6 mL which was poured into the mixture solution with an extra stirring time of 1.5 h. The optimal photocatalyst WUopt had porous and wrinkled configurations. Its light absorption edge was 524 nm while that of UCN was 465 nm. The band gap of WUopt was 2.13 eV, 0.3 eV less than that of UCN. Therefore, the recombination rate of photo-generated electron-hole pairs of WUopt reduced significantly. The removal rate of WUopt on RhB was 97.3%. By contrast, the removal rate of UCN was much lower (53.4%). WUopt retained a high RhB removal rate, it was 5.5% lower than the initial one after being reused for five cycles. The photodegradation mechanism was facilitated through the strong oxidation behaviors from the active free radicals ·O2-, ·OH and h+ generated by WUopt under the visible light irradiation.

One quick and simple fixation method: posterior malleolus fractures in spiral tibial fractures.

OBJECTIVE: Spiral fracture of tibia combined with posterior malleolar fracture (PMF) is a special and regular injury. There is no uniform fixation method for PMF in this kind of injury. Intramedullary nail is the first choice for the treatment of tibial spiral fracture. We proposed a minimally invasive percutaneous screw combined with intramedullary nail technology to fix the PMF in the tibial spiral fracture. This study aims to explore the effectiveness and advantages of this technology. MATERIALS AND METHODS: From January 2017 to February 2020, 116 cases of spiral fracture of tibia combined with PMF who were operated in our hospital were divided into Fixation Group (FG) and No Fixation Group (NG) according to whether PMF was fixed. After minimally invasive percutaneous screw fixation of ankle fracture in FG patients, the tibial intramedullary nail was inserted to fix the fracture. Collected the operation and postoperative recovery of the two groups of patients, including the operation time, intraoperative blood loss, AOFAS score, VAS score and dorsiflexion restriction of ankle joint at the last follow-up, and compared whether there is any difference between the two groups of patients. RESULTS: The fracture of both groups healed.2 patients in NG had secondary displacement of PMF during operation, and the fracture finally healed after fixation. There were statistical differences between the two groups in terms of operation time, AOFAS score and weight bearing time. The operation time of FG was 67.9±11.2 min, and that of NG was 60.8±9.4 min; The weight bearing time of FG was 57.35±34.72 days, and that of NG was 69.17±21.43 days; The AOFAS score of FG was 92.50±3.46, and that of NG was 91.00±4.16. There were no significant difference in blood loss, VAS and dorsiflexion restriction of ankle joint between the two groups. The blood loss of FG was 66.8±12.3 ml, the blood loss of NG was 65.6±11.7 ml, the VAS score of FG was 1.37±0.47, the VAS score of NG was 1.43±0.51, the dorsiflexion restriction of FG was 5.8±4.1; the NG was 6.1±5.7. CONCLUSION: For the injury of tibial spiral fracture combined with PMF, our fixation technology can achieve minimally invasive fixation of PMF with percutaneous screws on the basis of intramedullary nail fixation of tibial fracture, promoting early functional exercise of ankle joint and early weight bearing of patients. This fixation technology is also characterized by simple and fast operation.

Ultrafine cobalt selenide nanowires tangled with MXene nanosheets as highly efficient electrocatalysts toward the hydrogen evolution reaction.

Hydrogen energy has attracted sustainable attention in the exploitation and application of advanced power-generator devices, and electrocatalysts for the hydrogen evolution reaction (HER) have been regarded as one of the core components in the current electrochemical hydrogen production systems. In this work, a facile and cost-effective bottom-up strategy is developed for the construction of 1D ultrafine cobalt selenide nanowires tangled with 2D Ti3C2Tx MXene nanosheets (CoSe NW/Ti3C2Tx) through an in situ stereo-assembly process. Such an architectural design endows the hybrid system not only with a large accessible surface for the rapid transportation of reactants, but also with numerous exposed CoSe edge sites, thereby generating substantial synergic coupling effects. The as-derived CoSe NW/Ti3C2Tx hybrid demonstrates competitive electrocatalytic properties toward the HER with a small onset potential of 84 mV, a low Tafel slope of 56 mV dec-1 and exceptional cycling performance, which are superior to those of bare CoSe and Ti3C2Tx materials. It is believed this promising nanoarchitecture may provide new possibilities for the design and construction of precious-metal-free electrocatalysts with high efficiency and great stability in the energy-conversion field.