Barakat Nasser A M, Amen Mohamed T, Al-Mubaddel Fahad S, Karim Mohammad Rezual, Alrashed Maher
Chemical Engineering Department, Minia University, PO Box 61519, El-Minia, Egypt.
Bionano System Engineering Department, College of Engineering, Chonbuk National University, PO Box 54896, Jeonju, South Korea.
J Adv Res. 2018 Dec 16;16:43-53. doi: 10.1016/j.jare.2018.12.003. eCollection 2019 Mar.
Synthesis of NiSn alloy nanoparticle-incorporated carbon nanofibers was performed by calcining electrospun mats composed of nickel acetate, tin chloride and poly(vinyl alcohol) under vacuum. The electrochemical measurements indicated that utilization of tin as a co-catalyst could strongly enhance the electrocatalytic activity if its content and calcination temperature were optimized. Typically, the nanofibers prepared from calcination of an electrospun solution containing 15 wt% SnCl at 700 °C have a current density almost 9-fold higher than that of pristine nickel-incorporated carbon nanofibers (77 and 9 mA/cm, respectively) at 30 °C in a 1.0 M urea solution. Furthermore, the current density increases to 175 mA/cm at 55 °C for the urea oxidation reaction. Interestingly, the nanofibers prepared from a solution with 10 wt% of co-catalyst precursor show an onset potential of 175 mV ( Ag/AgCl) at 55 °C, making this proposed composite an adequate anode material for direct urea fuel cells. Optimization of the co-catalyst content to maximize the generated current density resulted in a Gaussian function peak at 15 wt%. However, studying the influence of the calcination temperature indicated that 850 °C was the optimum temperature because synthesizing the proposed nanofibers at 1000 °C led to a decrease in the graphite content, which dramatically decreased the catalyst activity. Overall, the study opens a new venue for the researchers to exploit tin as effective co-catalyst to enhance the electrocatalytic performance of the nickel-based nanostructures. Moreover, the proposed co-catalyst can be utilized with other functional electrocatalysts to improve their activity toward oxidation of different fuels.
通过在真空条件下煅烧由醋酸镍、氯化锡和聚乙烯醇组成的电纺垫来合成掺有NiSn合金纳米颗粒的碳纳米纤维。电化学测量表明，如果锡作为助催化剂的含量和煅烧温度得到优化，其利用可以强烈提高电催化活性。通常，在700℃煅烧含有15 wt% SnCl的电纺溶液制备的纳米纤维，在1.0 M尿素溶液中于30℃时的电流密度几乎比原始掺镍碳纳米纤维（分别为77和9 mA/cm²）高9倍。此外，对于尿素氧化反应，在55℃时电流密度增加到175 mA/cm²。有趣的是，由含有10 wt%助催化剂前驱体的溶液制备的纳米纤维在55℃时的起始电位为175 mV（Ag/AgCl），这使得这种提议的复合材料成为直接尿素燃料电池的合适阳极材料。将助催化剂含量优化以最大化产生的电流密度，在15 wt%处得到一个高斯函数峰。然而，研究煅烧温度的影响表明850℃是最佳温度，因为在1000℃合成提议的纳米纤维会导致石墨含量降低，这显著降低了催化剂活性。总体而言，该研究为研究人员开辟了一个新途径，以利用锡作为有效的助催化剂来增强镍基纳米结构的电催化性能。此外，提议的助催化剂可与其他功能性电催化剂一起使用，以提高它们对不同燃料氧化的活性。
