物理化学学报2023，Vol.39Issue(12)：103-112,10.DOI:10.3866/PKU.WHXB202303028
氮掺杂石墨烯气凝胶锚定RuP纳米粒子用于水合肼氧化辅助产氢
RuP Nanoparticles Anchored on N-doped Graphene Aerogels for Hydrazine Oxidation-Boosted Hydrogen Production
摘要
Abstract
'Green hydrogen'is a promising clean energy carrier for use instead of traditional fuels.For obtaining'green hydrogen',electrochemical water splitting has been receiving considerable attention due to its eco-friendly and low-cost properties.However,the sluggish kinetics of the anodic oxygen evolution reaction(OER)reduces the efficiency of hydrogen production.Accordingly,the hydrazine oxidation reaction(HzOR)with low theoretical potential(-0.33 V vs.RHE)has been proposed as a reasonable alternative for the OER.In this study,graphene aerogel(GA)was utilized as a conductive substrate with a 3D porous framework.RuⅢ-polyethyleneimine(RuⅢ-PEI)complexes were adsorbed on the GA surface.Phytic acid(PA)was further adsorbed to form RuⅢ-PEI-GA-PA hybrids through the hydrogen bond interaction between PA and PEI,which can serve as a precursor to synthesize RuP nanoparticles anchored on N-doped GA(RuP/N-GA)through the phosphorization reaction.In the pyrolysis process,the ultra-small RuP was formed at the GA surface.Additionally,the decomposition of PEI and PA can introduce abundant N and P heteroatoms into the structure of GA.As a result,RuP/N-GA hybrids achieve efficient HzOR with a low working potential of-54 mV at 10 mA.cm-2.Moreover,the novel RuP/N-GA hybrids with low Ru loading also exhibit a promising hydrogen evolution reaction(HER)activity with an overpotential of-19.6 mV at 10 mA.cm-2.Among various RuP/N-GA hybrids,the Tafel plot of HER at RuP/N-GA-900 reveals the smallest value to be 37.03 mV.dec-1,which affords the fastest HER kinetics.Meanwhile,the result suggests that the HER at RuP/N-GA-900 undergoes a Heyrovsky mechanism similar to that of Pt.The theoretical results revealed that the anchored structure and the presence of N heteroatoms can promote the HzOR on RuP nanoparticles.The free energy of hydrazine molecular adsorption on RuP/N-GA was-0.68 eV,indicating that N-doping in the RuP/N-GA structure can adjust the electronic structure of the Ru active site,which also contributes to the enhanced HzOR activity of the Ru site.Additionally,RuP/N-GA hybrids exhibited excellent cycling and long-term stability for both HER and HzOR,superior to those of commercial Pt/C.Based on the bifunctional activity of RuP/N-GA hybrids,the constructed two-electrode hydrazine split system exhibits an extremely low cell voltage of 41 mV at 10 mA.cm-2 for the hydrogen production,which achieves the goal of energy-saved hydrogen production at low voltage.The excellent electrocatalytic activity of RuP/N-GA hybrids is attributed to the ultrasmall RuP nanoparticles for abundant Ru active sites.Meanwhile,the synergistic effect between N-doping in GA frameworks with RuP nanoparticles contributes to the activity enhancement of RuP/N-GA hybrids,in which the 3D porous N-GA with few-layer morphology accelerates the electron and mass transfer and the electron interaction between N-GA and RuP nanoparticles promotes the electrocatalytic activity of RuP nanoparticles for both HER and HzOR.This study extends the bifunctional electrocatalyst for the HER and HzOR to achieve energy-saved hydrogen production and sheds new light on the design and synthesis of advanced electrocatalysts via the adsorption-phosphatization method.关键词
磷化钌/石墨烯气凝胶/锚定结构/肼氧化反应/析氢反应Key words
Ruthenium phosphide/Graphene aerogel/Anchored structure/Hydrazine oxidation reaction/Hydrogen evolution reaction分类
化学化工引用本文复制引用
王正慜,洪庆玲,王晓慧,黄昊,陈煜,李淑妮..氮掺杂石墨烯气凝胶锚定RuP纳米粒子用于水合肼氧化辅助产氢[J].物理化学学报,2023,39(12):103-112,10.基金项目
The project was supported by the National Natural Science Foundation of China(21972089,22002083),the Science and Technology Innovation Team of Shaanxi Province(2023-CX-TD-27),and the Fundamental Research Funds for the Central Universities(GK202202001).国家自然科学基金(21972089,22002083),陕西省创新能力支撑计划(2023-CX-TD-27)及中央高校基本科研业务费(GK202202001)资助项目 （21972089,22002083）
