Hokkaido University · 에너지
Weiren Cheng 교수의 연구실은 전기화학적 에너지 변환 및 저장 시스템을 위한 고성능 산소 반응 촉매를 개발하는 데 초점을 맞추고 있습니다. 특히, 니켈, cobalt, copper 기반의 나노구조적 금속 유기 프레임워크(MOF) 및 이들의 복합체를 활용해 산소 환원 반응(ORR)과 산소 발생 반응(OER)에 뛰어난 활성도와 안정성을 동시에 확보하는 연구를 진행하고 있습니다. 실시간 분석 기법(예: 옵레인 시닝고 XAFS)을 활용한 촉매의 작동 메커니즘 규명도 핵심 과제입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Developing noble-metal-free bifunctional oxygen electrocatalysts is of great significance for energy conversion and storage systems. Herein, we have developed a transformation method for growing NiMn-based bimetal-organic framework (NiMn-MOF) nanosheets on multi-channel carbon fibers (MCCF) as a bifunctional oxygen electrocatalyst. Owing to the desired components and architecture, the MCCF/NiMn-MOFs manifest comparable electrocatalytic performance towards oxygen reduction reaction (ORR) with the
Conductive metal-organic framework (MOF) materials have been recently considered as effective electrocatalysts. However, they usually suffer from two major drawbacks, poor electrochemical stability and low electrocatalytic activity in bulk form. Here, we have developed a rational strategy to fabricate a promising electrocatalyst composed of a nanoscale conductive copper-based MOF (Cu-MOF) layer fully supported over synergetic iron hydr(oxy)oxide [Fe(OH) <i><sub>x</sub></i> ] nanoboxes. Owing to
The structural dynamics of the solid-liquid interfaces (SLEIs) determines the chemistry in all electrochemical processes. Here, by combining multiple operando synchrotron spectroscopies, we identify at the atomic level a general evolution of single-atom Ni at SLEIs into a near-free atom state in the electrochemical oxygen reduction reaction (ORR). We uncover that the single-atom Ni at SLEIs tends to be dynamically released from the nitrogen-carbon substrate and then forms a near-free, isolated-z
The development of efficient oxygen electrocatalysts and understanding their underlying catalytic mechanism are of significant importance for the high-performance energy conversion and storage technologies. Herein, we report novel CoCu-based bimetallic metal-organic framework nanoboxes (CoCu-MOF NBs) as promising catalysts toward efficient electrochemical oxygen evolution reaction (OER), fabricated via a successive cation and ligand exchange strategy. With the highly exposed bimetal centers and
The synthesis of atomically thin transition-metal oxide nanosheets as a conceptually new class of materials is significant for the development of next-generation electronic and magnetic nanodevices but remains a fundamental chemical and physical challenge. Here, based on a "template-assisted oriented growth" strategy, we successfully synthesized half-unit-cell nanosheets of a typical transition-metal oxide α-Fe2O3 that show robust intrinsic ferromagnetism of 0.6 μB/atom at 100 K and remain ferro
Fundamental insights into the structural evolution of oxygen electrocatalysts under operating conditions are of substantial importance for designing efficient catalysts. Here, on the basis of operando x-ray absorption fine structure spectroscopy, we probe the in situ activation of Br-confined conductive Ni-based metal-organic framework (Br-Ni-MOF) hollow prisms toward an active oxygen electrocatalyst during the oxygen evolution reaction (OER) process. The successive structural transformations fr
The development of noble-metal-free, acid-compatible oxygen electrocatalysts and monitoring their active sites’ evolution under working conditions are crucial for global renewable energy storage and conversion. Here, we present a new type of hetero-N-coordinated Co (HNC-Co) single sites, with Co active centers bonding to hetero pyridinic- and amino-N ligands, as an efficient oxygen evolution reaction (OER) electrocatalyst in an acidic medium. The atomically dispersed HNC-Co electrocatalyst could
Oxygen-involved electrocatalytic processes, including the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), are central to a series of advanced modern energy and conversion technologies, such as water electrolyzers, fuel cells, and CO<sub>2</sub> reduction or N<sub>2</sub> fixation devices. A comprehensive and in-depth understanding of the charge transfer and energy conversion process that ubiquitously occurs over solid-liquid electrochemical interfaces during oxygen electroca
We design a 3D metal-vacancy-solid-solution NiAl<sub>δ</sub>P nanowall array bifunctional electrocatalyst, which is highly efficient in pH-universal overall water splitting.
We report a newly designed Au cluster-nanoparticle/C<sub>3</sub>N<sub>4</sub>photocatalyst for realizing efficient plasmonic hot-electron injection, which could effectively improve the hydrogen production rate by 6–20 times in the 400–900 nm range.
Direct water splitting in pure water relying on photocatalysis is an effective way to realize an efficient solar to chemical fuel conversion toward solving the global energy crisis and environmental problems. Here, via a “high-valence metal single-atom confinement” strategy, we effectively modify the valence band structure of the semiconductor photocatalyst toward a spontaneous photocatalytic water splitting in pure water. This as-prepared PtII–C3N4 could achieve an efficient photocatalytic wate
We design Mn-confined CoOOH nanosheets that actively catalyze water oxidation with a low onset potential of 1.43 V<italic>vs.</italic>RHE and a small Tafel slope of ∼38 mV dec<sup>−1</sup>.
Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the core reactions of a series of advanced modern energy and conversion technologies, such as fuel cells and metal-air cells. Among all kinds of oxygen electrocatalysts that have been reported, single-atom catalysts (SACs) offer great development potential because of their nearly 100% atomic utilization, unsaturated coordination environment, and tunable electronic structure. In recent years, numerous SACs with enriched activ
To efficiently transform absorbed photons to chemical energy is highly desired for the full utilization of visible light in solar hydrogen generation process. Here, a highly active photoanode consisting of a thin NixFe2–xO3 overlayer on the surface of hematite nanotube has been constructed to raise the utilization of the photoexcited carriers by Fe2O3 in the visible spectrum. We find that the obtained overlayer photoanodes promote the charge migration of photogenerated carriers to the surface, a