摘要
Al掺杂钛酸锶(SrTiO_(3):Al)是目前唯一表观量子效率可接近100%的粉末光催化全分解水体系.深入研究其高效光生电荷分离与表面反应效率的作用机制,对于合理设计高性能光催化剂、推进规模化太阳能制氢具有重要意义.可控合成光催化全分解水性能优异的SrTiO_(3):Al模型体系,是揭示其高效光生电荷利用机制的基础.本研究系统地探讨了熔盐法制备SrTiO_(3):Al过程中合成温度、Al_(2)O_(3)种类与添加量以及前驱体SrTiO_(3)的性质对样品光催化全分解水性能的影响.研究结果表明,SrTiO_(3):Al的最优合成温度为1423 K;适宜的Al_(2)O_(3)源为γ-Al_(2)O_(3)和含有80%α相的Al_(2)O_(3);对于水热合成的SrTiO_(3)前驱体,最优Al_(2)O_(3)添加量为1 mol%(相对于SrTiO_(3));而对于固相合成的SrTiO_(3),最优Al_(2)O_(3)添加量为1~2 mol%.其中,结晶性较高的固相法合成的SrTiO_(3)是制备最优光催化性能的2%-SrTiO_(3):Al的理想前驱体.
Al-doped SrTiO_(3)(SrTiO_(3):Al)is currently the only known particulate photocatalyst that achieves near-unity apparent quantum efficiency(AQE)for overall water splitting.The underlying mechanism by which Al doping enhances photocatalytic performance has attracted widespread attention,as uncovering how photogenerated charges are efficiently utilized is critical for the rational design of high-performance photocatalysts.Such insights are essential for advancing scalable solar-to-hydrogen conversion technologies.Developing SrTiO_(3):Al model photocatalysts with well-defined structures and high activity is therefore fundamental to elucidating the mechanisms behind their exceptional charge separation and surface reaction efficiencies.In this work,we systematically investigate the effects of various synthesis parameters on the photocatalytic performance of SrTiO_(3):Al prepared via a flux method.The parameters studied include the temperature,the phase and amount of Al_(2)O_(3)dopant,and the morphology and crystallinity of the SrTiO_(3)precursor.The photocatalytic activity of SrTiO_(3):Al exhibits a volcano-type dependence on the synthesis temperature,with the highest activity achieved at 1423 K.The crystal structure of the Al_(2)O_(3)dopant also plays a critical role:γ-Al_(2)O_(3)and partially crystallineα-Al_(2)O_(3)(with 80%α-phase)lead to markedly improved performance.The optimal amount of Al_(2)O_(3)added depends strongly on the type of precursor,1 mol%for hydrothermally synthesized precursors and 1~2 mol%for those prepared via solid-state synthesis.At a fixed Al_(2)O_(3)content of 2 mol%,the properties of the precursor significantly affect the final particle morphology,size distribution,and crystallinity.The best-performing sample exhibits high crystallinity and a narrow particle size distribution centered around 200 nm.Al doping in SrTiO_(3):Al not only repairs lattice defects and suppresses excessive grain growth but also promotes the exposure of high-index facets.These findings suggest that multiple synthesis parameters synergistically govern the doping concentration and spatial distribution of Al,ultimately modulating lattice quality,particle structure,and charge separation efficiency—thereby determining the overall water splitting activity of SrTiO_(3):Al.
作者
罗雅玲
庄展洋
范峰滔
李灿
Luo Yaling;Zhuang Zhanyang;Fan Fengtao;Li Can(State Key Laboratory of Catalysis,Dalian National Laboratory for Clean Energy,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023;University of Chinese Academy of Sciences,Beijing 100049)
出处
《化学学报》
北大核心
2025年第6期608-615,共8页
Acta Chimica Sinica
基金
国家自然科学基金(No.22088102)资助。
关键词
铝掺杂钛酸锶
光催化全分解水
熔盐法
粉末光催化剂
Al doped SrTiO_(3)
photocatalytic overall water splitting
flux method
particulate photocatalyst
