Bhattacharya Deepra, Kole Subarna, Kizilkaya Orhan, Strzalka Joseph, Angelopoulou Polyxeni P, Sakellariou Georgios, Cao Dongmei, Arges Christopher G
Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA, 70803, USA.
Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, LA, 70806, USA.
Small. 2021 Jun;17(25):e2100437. doi: 10.1002/smll.202100437. Epub 2021 May 14.
Self-assembled block copolymers are promising templates for fabricating thin film materials with tuned periodic feature sizes and geometry at the nanoscale. Here, a series of nanostructured platinum and iridium oxide electrocatalysts templated from poly(styrene)-block-poly(vinyl pyridine) (PSbPVP) block copolymers via an incipient wetness impregnation (IWI) pathway is reported. Both nanowire and nanocylinder electrocatalysts of varying feature sizes are assessed and higher catalyst loadings are achieved by the alkylation of the pyridine moieties in the PVP block prior to IWI. Electrocatalyst evaluations featuring hydrogen pump and water electrolysis demonstrations are carried out on interdigitated electrode (IDE) chips flexible with liquid supporting electrolytes and thin film polymer electrolytes. Notably, the mass activities of the nanostructured electrocatalysts from alkylated block copolymer templates are 35%-94% higher than electrocatalysts from non-alkylated block copolymer templates. Standing cylinder nanostructures lead to higher mass activities than lamellar variants despite their not having the largest surface area per unit catalyst loading demonstrating that mesostructure architectures have a profound impact on reactivity. Overall, IDE chips with model thin film electrocatalysts prepared from self-assembled block copolymers offer a high-throughput experimental method for correlating electrocatalyst nanostructure and composition to electrochemical reactivity.
自组装嵌段共聚物是制备具有纳米级周期性特征尺寸和几何形状的薄膜材料的有前途的模板。在此，报道了一系列通过初湿浸渍（IWI）途径由聚（苯乙烯）-嵌段-聚（乙烯基吡啶）（PSbPVP）嵌段共聚物模板化的纳米结构铂和氧化铱电催化剂。评估了不同特征尺寸的纳米线和纳米柱电催化剂，并通过在IWI之前对PVP嵌段中的吡啶部分进行烷基化来实现更高的催化剂负载量。在具有液体支撑电解质和薄膜聚合物电解质的叉指电极（IDE）芯片上进行了以氢泵和水电解演示为特色的电催化剂评估。值得注意的是，来自烷基化嵌段共聚物模板的纳米结构电催化剂的质量活性比来自非烷基化嵌段共聚物模板的电催化剂高35%-94%。直立圆柱纳米结构比层状变体具有更高的质量活性，尽管它们在单位催化剂负载量下没有最大的表面积，这表明介观结构对反应性有深远影响。总体而言，由自组装嵌段共聚物制备的具有模型薄膜电催化剂的IDE芯片提供了一种高通量实验方法，用于将电催化剂纳米结构和组成与电化学反应性相关联。
