Kim Ga-Yoon, Yoon Ki Ro, Shin Kihyun, Jung Ji-Won, Henkelman Graeme, Ryu Won-Hee
Department of Chemical and Biological Engineering, Sookmyung Women's University, 100 Cheongpa-ro 47-gil, Yongsan-gu, Seoul, 04310, Republic of Korea.
Advanced Textile R&D Department, Korea Institute of Industrial Technology (KITECH) 143, Hanggaul-ro, Sangnok-gu, Ansan-si, Gyeonggi-do, 15588, Republic of Korea.
Small. 2021 Nov;17(47):e2103755. doi: 10.1002/smll.202103755. Epub 2021 Oct 29.
Black valve metal oxides with low oxygen vacancies are identified to be promising for various industrial applications, such as in gas sensing, photocatalysis, and rechargeable batteries, owing to their high reducibility and stability, as well as considerable fractions of low-valent metal species and oxygen vacancies in their lattices. Herein, the nanofiber (NF) of black oxygen-deficient tungsten trioxide (WO ) is presented as a versatile and robust support for the direct growth of a platinum catalyst for oxygen reduction reaction (ORR). The nonstoichiometric, poorly crystallized black WO NFs are prepared by electrospinning the W precursor into NFs followed by their low-temperature (650 °C) reductive calcination. The black WO NFs have adequate electrical conductivity owing to their decreased bandgap and amorphous structure. Remarkably, the oxygen-deficient surface (surface O/W = 2.44) facilitates the growth of small Pt nanoparticles, which resist aggregation, as confirmed by structural characterization and computational analysis. The Pt-loaded black WO NFs outperform the Pt-loaded crystalline white WO NFs in both the electrochemical ORR activity and the accelerated durability test. This study can inspire the use of oxygen-deficient metal oxides as supports for other electrocatalysts, and can further increase the versatility of oxygen-deficient metal oxides.
具有低氧空位的黑色阀金属氧化物因其高还原性和稳定性，以及晶格中相当比例的低价金属物种和氧空位，被认为在各种工业应用中具有潜力，如气体传感、光催化和可充电电池等领域。在此，黑色缺氧三氧化钨（WO ）纳米纤维（NF）被提出作为一种通用且坚固的载体，用于直接生长用于氧还原反应（ORR）的铂催化剂。通过将钨前驱体静电纺丝成纳米纤维，然后进行低温（650℃）还原煅烧，制备出非化学计量、结晶度差的黑色WO 纳米纤维。由于其带隙减小和非晶结构，黑色WO 纳米纤维具有足够的导电性。值得注意的是，缺氧表面（表面O/W = 2.44）促进了小铂纳米颗粒的生长，这些颗粒抗团聚，结构表征和计算分析证实了这一点。负载铂的黑色WO 纳米纤维在电化学ORR活性和加速耐久性测试中均优于负载铂的结晶白色WO 纳米纤维。这项研究可以启发人们将缺氧金属氧化物用作其他电催化剂的载体，并进一步提高缺氧金属氧化物的通用性。
