寻找并开发经济可行、稳定可靠且高效的光电极材料是光电化学(PEC)水分解领域亟待解决的关键挑战。在众多候选材料中,氧化钨(WO_(3))凭借其独特的物理化学性质脱颖而出,成为备受青睐的优选材料之一。为了进一步优化氧化钨(WO_(3))光电...寻找并开发经济可行、稳定可靠且高效的光电极材料是光电化学(PEC)水分解领域亟待解决的关键挑战。在众多候选材料中,氧化钨(WO_(3))凭借其独特的物理化学性质脱颖而出,成为备受青睐的优选材料之一。为了进一步优化氧化钨(WO_(3))光电极的光电性能,本文选用了无毒、化学稳定性优异且资源丰富的α-Fe_(2)O_(3),通过简单的水热法将其与WO_(3)有效结合,成功构筑了全氧化物WO_(3)/α-Fe_(2)O_(3)复合电极,并对其组织结构、光学性能和光电化学性能进行了表征分析。实验结果表明,在1.23 V vs.RHE的偏压条件下,该复合电极的光电流密度达到了0.56 mA/cm^(2),是WO_(3)光电极的1.87倍。这可归因于多方面的协同效应:WO_(3)一维纳米棒结构为电子提供了高效的传输通道,确保了高导电性;α-Fe_(2)O_(3)的引入不仅提高了可见光利用效率,还与WO_(3)形成了异质结结构,有效抑制了电子-空穴对的复合,促进了载流子的高效分离与传输,从而实现了光电性能的提高。本文为构筑经济、稳定且高效的光电极材料提供了一些理论参考。展开更多
The bulk amorphous alloy Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)was prepared by copper-mold inject casting.Its microstructural transformation and electrochemical properties were investigated.The microstructures of Mg_(60)Ni_...The bulk amorphous alloy Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)was prepared by copper-mold inject casting.Its microstructural transformation and electrochemical properties were investigated.The microstructures of Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)amorphous alloy during charge and discharge cycling were characterized by XRD and SEM.The electrochemical performances of the alloy were tested by an automatic charge and discharge apparatus.The results show that the amorphous structure transforms into crystallized one step by step and Mg_(2)NiH_(4),Mg_(2)Ni and Mg(OH)_(2)phases are formed gradually during the process of hydrogenation and dehydrogenation.Furthermore,the result of electrochemical characteristics testing shows that the change process of discharge capacity for Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)amorphous alloy can be divided into four stages and the highest discharge capacity reaches 410.5 mAh/g.It is found that the amorphous structure may be a critical factor to obtain the maximum discharge capacity.展开更多
文摘寻找并开发经济可行、稳定可靠且高效的光电极材料是光电化学(PEC)水分解领域亟待解决的关键挑战。在众多候选材料中,氧化钨(WO_(3))凭借其独特的物理化学性质脱颖而出,成为备受青睐的优选材料之一。为了进一步优化氧化钨(WO_(3))光电极的光电性能,本文选用了无毒、化学稳定性优异且资源丰富的α-Fe_(2)O_(3),通过简单的水热法将其与WO_(3)有效结合,成功构筑了全氧化物WO_(3)/α-Fe_(2)O_(3)复合电极,并对其组织结构、光学性能和光电化学性能进行了表征分析。实验结果表明,在1.23 V vs.RHE的偏压条件下,该复合电极的光电流密度达到了0.56 mA/cm^(2),是WO_(3)光电极的1.87倍。这可归因于多方面的协同效应:WO_(3)一维纳米棒结构为电子提供了高效的传输通道,确保了高导电性;α-Fe_(2)O_(3)的引入不仅提高了可见光利用效率,还与WO_(3)形成了异质结结构,有效抑制了电子-空穴对的复合,促进了载流子的高效分离与传输,从而实现了光电性能的提高。本文为构筑经济、稳定且高效的光电极材料提供了一些理论参考。
基金National Natural Science Foundation of China(50972066)
文摘The bulk amorphous alloy Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)was prepared by copper-mold inject casting.Its microstructural transformation and electrochemical properties were investigated.The microstructures of Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)amorphous alloy during charge and discharge cycling were characterized by XRD and SEM.The electrochemical performances of the alloy were tested by an automatic charge and discharge apparatus.The results show that the amorphous structure transforms into crystallized one step by step and Mg_(2)NiH_(4),Mg_(2)Ni and Mg(OH)_(2)phases are formed gradually during the process of hydrogenation and dehydrogenation.Furthermore,the result of electrochemical characteristics testing shows that the change process of discharge capacity for Mg_(60)Ni_(23.6)Y_(0.5)La_(15.9)amorphous alloy can be divided into four stages and the highest discharge capacity reaches 410.5 mAh/g.It is found that the amorphous structure may be a critical factor to obtain the maximum discharge capacity.
