ABSTRACT
Hydrogen evolution from water electrolysis is one of the effective ways to obtain clean hydrogen energy in the future. Pt-based materials are the efficient catalysts in hydrogen evolution reaction, but it is expensive, difficult to recycle, which impedes its application in the development of hydrogen energy and economy. Therefore, it is the key trend to develop efficient non-noble metal electrocatalysts with the aim of providing cost-competitive hydrogen energy. In this review, we highlighted the recent research efforts toward the synthesis of noble metal-free electrocatalysts for the hydrogen evolution reaction ( HER) , mainly focusing on nanomaterial catalysts supported on carbon fiber materials. We reviewed several important kinds of heterogeneous non-noble metal electrocatalysts, including sulfides, selenides, carbides, phosphides, and oxides. In the discussion, emphasis was given to the synthetic methods of these HER electrocatalysts, and the strategies for performance improvement. In addition, this paper also briefly summarized the application of carbon fiber material as substrate in the field of electroanalytical chemistry.
ABSTRACT
Objective To investigate the therapeutic effect of three-dimensional interactive reduction of femoral neck and shaft in treatment of irreducible femoral neck fracture.Methods The study enrolled 40 patients with irreducible femoral neck fractures treated by three-dimensional interactive reduction of femoral neck/shaft and internal fixation with three cannulated screws from June 2011 to July 2013 (study group).Frontal and lateral X-ray films were taken after operation.Garden index was used to evaluate the fracture reduction quality and Harris hip score was recorded.Meanwhile,a retrospective analysis was performed on 32 patients with irreducible femoral neck fractures treated by open reduction and internal fixation with cannulated screws between January 2008 and December 2010 (control group).Results Patients in study group obtained satisfactory reduction by minimally traumatic closed reduction.According to the Garden index,fracture reduction quality was level 1 in 24 patients and level 2 in 16 patients.Thirty-two patients were followed up for 12-28 months (mean,21 months),which showed fracture healing.At the final follow-up,Harris hip score was 87 points (range,61-100 points) and 4 patients had femoral head avascular necrosis.By contrast,6 patients in control group showed fracture nonunion.At the final follow-up,Harris hip score was 60 points (range,20-100 points) and 8 patients had femoral head avascular necrosis.Conclusion Three-dimensional interactive reduction of femoral neck and shaft provides good hip function recovery and decreased incidence of femoral head avascular necrosis and fracture disunion compared with the open reduction and internal fixation.