21 Dec 2019, our work "Real-Time Observation of Anion Reaction in High Performance Al Ion Batteries" has been accepted on ACS Applied Materials & Interfaces

Tien-Sheng Lee,1# Shivaraj B. Patil,1# Yu-Ting Kao,1# Ji-Yao An,1 Yi-Cheng Lee,1 Ying-Huang Lai,1 Chung-Kai Chang,2 Yu-Song Cheng,2 Yu-Chun Chuang,2 Hwo-Shuenn Sheu,2 Chun-Hsing Wu,3 Chang-Chung Yang,3 Ruey-Hwa Cheng,4 Chung-Yu Lee,4 Po-Yang Peng,4 Liang-Hsun Lai,4 Hsin-Hung Lee,4 Di-Yan Wang1*

Recently, aluminum ion batteries (AIBs) have attracted great attention across the globe by virtue of its massive gravimetric and volumetric capacities in addition to its high abundance. Though carbon derivatives are excellent cathodes for AIBs, there is much room for further development. In this study, flexuous graphite (FG) was synthesized by a simple thermal shock treatment and, for the first time, an Al/FG battery was applied as a cathode for AIBs to reveal the real-time intercalation of AlCl4- into FG with high flexibility using in situ scanning electron microscope (SEM) measurements exclusively. Similarly, in situ X-ray diffraction (XRD) and in situ Raman techniques have been used to understand the anomalous electrochemical behavior of FG. It was found that FG adopts a unique integrated intercalation–adsorption mechanism where it follows an intercalation mechanism potential above 1.5 V and an adsorption mechanism potential below 1.5 V. This unique integrated intercalation–adsorption mechanism allows FG to exhibit superior properties, like high capacity (≥140 mAh/g), remarkable long-term stability (over 8000 cycles), excellent rate retention (93 mAh/g at 7.5 A/g) and extremely rapid charging and slow discharging.

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Dec. 8 2019, Congratulations "Yi-Chia receive an research thesis award in 2019 化學年會"

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Photoactive Earth-Abundant Iron Pyrite Catalysts for Electrocatalytic Nitrogen Reduction Reaction

Chia-Che Chang, Shin-Ren Li, Hung-Lung Chou,* Yi-Cheng Lee, Shivaraj Patil, Ying-Sheng Lin, Chun-Chih Chang, Yuan Jay Chang, and Di-Yan Wang*

Small, Just Accepted Manuscript
Publication Date (Web): October 14, 2019
The generation of ammonia, hydrogen production and nitrogen purification are considered as energy intensive processes accompanied with large amount of CO2 emission. The electrochemical method assisted by photo energy has been widely utilized for the chemical energy conversion. In this work, the earth-abundant iron pyrite (FeS2) nanocrystals grown on carbon fiber paper (FeS2/CFP) was found to be an electrochemical and photoactive catalysts for nitrogen reduction reaction (NRR) under ambient temperature and pressure. The electrochemical results revealed that FeS2/CFP achieved a high Faradaic efficiency (FE) ~14.14% and NH3 yield rate~ 0.096 mg/min at 0.6 V versus RHE electrode in 0.25 M LiClO4. During proceeding electrochemical catalytic reaction, the crystal structure of FeS2/CFP remained cubic pyrite phase analyzed by in-situ XRD measurement. Also, With near infrared laser irradiation (808 nm), NH3 yield rate of FeS2/CFP catalyst can be slightly improved to (0.1 mg/min) with high FE of 14.57%. Furthermore, density functional theoretical (DFT) calculations demonstrated that N2 molecule had strong chemical adsorption energy on the iron atom of FeS2. Overall, the iron pyrite-based materials have proven to be a potential electrocatalyst with photoactive behavior for ammonia production in practical applications.
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13 May. 2019. our work "Creation of three-dimensional textured graphene/Si Schottky junction photocathode for enhanced photoelectrochemical efficiency and stability" has been accepted by Advanced Energy Materials

Creation of three-dimensional textured graphene/Si Schottky junction photocathode for enhanced photoelectrochemical efficiency and stability

Che-Kuei Ku, Po-Hsien Wu, Cheng-Chu Chung, Chun-Chi Chen, Kai-Jie Tsai, Hung-Ming Chen, Yu-Cheng Chang, Cheng-Hao Chuang, Chuan-Yu Wei, Cheng-Yen Wen, Tzu-Yao Lin,1 Hsuen-Li Chen, Yen-Shang Wang, Zhe-Yu Lee, Jun-Ru Chang, Chih-Wei Luo, Di-Yan Wang,* Bing Joe Hwang,* Chun-Wei Chen*

This work demonstrates a novel three-dimensional pyramid-like graphene/p-Si Schottky junction photocathode for H2 production based on the unique advantages of excellent carrier transport, high transparency and superior corrosion protection of graphene. The formation of graphene/Si Schottky junctions with 3D architecture is a promising approach to improve the performance and durability of Si-based photoelectrochemical systems for water splitting or solar-to-fuel conversion.

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Apr. 2019. our work "Plasmon-Enhanced Hydrogen Evolution on Specific Facet of Silver Nanocrystals" has been published on Chemistry of Materials in ASAP.

Plasmon-Enhanced Hydrogen Evolution on Specific Facet of Silver Nanocrystals

Tsung-Rong Kuo,*ab, Yi-Cheng Lee,c Hung-Lung Chou,*d Chuan-Yu Wei,e Cheng-Yen Wen,e Swathi MG,c Yi-Hsuan Chang,c Xi-Yu Pana and Di-Yan Wang*c

https://pubs.acs.org/doi/full/10.1021/acs.chemmater.9b00652

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Hydrogen evolution reaction (HER) from electrocatalytic water splitting is a promising technology to provide clean energy with low environmental impact for the future. In this work, plasmonic silver nanocubes (AgNCs) with (100) facet and silver nanooctahedrons (AgNOs) with (111) facet were applied as the light-harvesting catalysts for enhancing hydrogen production in the plasmon-activated HER electrochemical system. As light harvesters, AgNCs and AgNOs can efficiently absorb light ranging from ultraviolet to near-infrared to generate hot electrons for facilitating electrocatalytic HER. Both AgNCs and AgNOs revealed the light-harvesting capability to improve HER activities with laser irradiation. Moreover, the current densities of AgNOs with (111) facet were higher than those of AgNCs with (100) facet for electrocatalytic HER under irradiations with three different laser wavelengths. The density function theory (DFT) simulations revealed the adsorption energy of the surfaces followed the order Ag(111) < Ag(100), indicating that the hydrogen could be easily desorbed on the Ag(111) surface for HER. Both the experimental HER results and DFT simulations expressed that AgNOs with (111) facet were the excellent light harvesters in this study. Based on the DFT simulations of the H-Ag(111) and H-Ag(100) systems, the findings could be extended to other plasmon-enhanced HER electrochemical systems and would enable electrocatalysts to be tailored at the atomic level.