Enhanced Hydrogen Evolution Efficiency Achieved by Atomically Controlled Platinum Deposited on Gold Nanodendrites with High-Index Surfaces

Ying-Huang Lai,1*Sin-Ren Li,1# Swathi M G,1#Hsiao-Tzu Chang,1# Yu-Bin Huang,1 Yen-Ken Li,1 Yu-Mei Chen,1 Shivaraj B. Patil,1Shu-Yi Chang,1 Po-Kai Chen,1 Chia-Che Chang,1 Yi-Chia Chen,1 Chih-Wen Pao,2 Jeng-Lung Chen,2 Chuan-Yu Wei,3 I-Kuan Lin,3 Hung-Lung Chou,4Chun-Jen Su,2U-Ser Jeng,2,5 Tsung-Rong Kuo,6 Cheng-Yen Wen,3,7,8 Di-Yan Wang1*

Just accepted by J. Mater. Chem. A

There have been lots of studies on hydrogen evolution reaction (HER) catalytic activity using ultralow loading of Pt catalysts or even Pt single atom catalysts as well. However, Pt single atom deposited on the surface of the carbon or metal oxide material showed some drawbacks, such as high possibility of Pt desorption from the supported material in the electrolyte. Besides, from the reaction mechanism perspective, each Pt atom in this type of catalyst was too far to achieve high HER efficiency via Tafel reaction pathway. In this work, gold nanodendrites (Au NDs) with high facet surface was chosen as the supported materials for studying the relation between the low loading amount of Pt atoms and reaction mechanism of HER activity. The atomic deposition of Pt atoms on the surface of Au NDs can be controlled effectively by using a constant-current synthetic method. It’s found that the HER electrocatalytic activity of ultralow Pt loading catalyst, Pt atoms to total surface atoms of Au NDs (O-Pt on Au NDs) was only 5.5%, could achieve high efficiency via Tafel reaction pathway, showing a low overpotential of ~18 mV at a current density of 10 mA cm−2 and a small Tafel slope of ~31 mV dec-1 which is close to that of commercial Pt/C with 20wt% Pt. Confirmed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Pt loading amount of O-Pt on Au NDs was ~3.8 ± 0.2mg/cm2 on a physical area of carbon fibre paper. The turnover frequency (TOF) of O-Pt on Au NDs was achieved to be 40.1 ± 2.5H2 s−1 at 50 mV. This work provides a feasible approach to control atomic deposition of Pt element on the specific substrate as active catalysts for various catalytic applications.

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Facile Fabrication of Highly-Stable and Wavelength-Tunable Tin based Perovskite Materials with Enhanced Quantum Yield via Cation Transformation Reaction

Jia-Ming Meng,1# Zhi-Xian Yang,1# Shivaraj B. Patil,1# Jou-Chun Lin,1# Chen-Hao Yeh,2 Yi-Chia Chen,1 Chih-Wen Pao,3 Jeng-Lung Chen,3 Wun-Yu Chen,4 Chin-Wei Lu,4 Tsung-Rong Kuo,5 Di-Yan Wang1*

just accepted by J. Phys. Chem. Lett.

Metal halide perovskites have attracted great attention for their superior light energy conversion applications. Herein, we demonstrated a facile synthesis of zero-dimensional Sn2+ perovskite Cs4-xMxSnBr6 (M= K+ and Rb+) material through cation transformation reaction at room temperature. Cs4SnBr6 NCs were mixed with pure metal bromide salts (KBr and RbBr) via mechanochemical process to successfully synthesize Cs4-xMxSnBr6 perovskite where transformation of Cs to mixed Cs/Rb and mixed Cs/K was achieved. By substituting different cations, the bright fluorescence of the Cs4-xMxSnBr6 was tuned from dim green to greenish-cyan while achieving the photoluminescence (PL) quantum yield of ~39 %. The crystal structure of Sn based perovskite with the substitution of K+ or Rb+ cations were determined by X-ray diffraction (XRD). Moreover, the Cs4-xMxSnBr6 demonstrated superior air-stability and exhibited a better photocatalytic activity for CO2 reduction reaction (CO2RR) with high selectivity of CH4 gas with higher yield rate compared to the pristine Cs4SnBr6 NCs.

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Facile Fabrication of Highly-Stable and Wavelength-Tunable Tin based Perovskite Materials with Enhanced Quantum Yield via Cation Transformation Reaction

Jia-Ming Meng,1# Zhi-Xian Yang,1# Shivaraj B. Patil,1# Jou-Chun Lin,1# Chen-Hao Yeh,2 Yi-Chia Chen,1 Chih-Wen Pao,3 Jeng-Lung Chen,3 Wun-Yu Chen,4 Chin-Wei Lu,4 Tsung-Rong Kuo,5 Di-Yan Wang1*

Electrocatalytic Reduction of NO3- to Ultrapure Ammonia on {200} Facet Dominant Cu Nanodendrites with High Conversion Faraday Efficiency

Shivaraj B. Patil,1Ting-Ran Liu,2 Hung-Lung Chou,3* YuBin Huang,1 Chia-Che Chang,1 Yi-Chia Chen,1 Ying-Sheng Lin,1 Hsin Li,1 Yi-Cheng Lee,1 Yuan Jay Chang,1 Ying-Huang Lai,1 Cheng-Yen Wen,2 Di-Yan Wang1*

Just Accepted by J. Phys. Chem. Lett.

Nitrate (NO3-) reduction reaction (NtRR) is considered as a green alternative method for conventional way of NH3 synthesis (Haber-Bosch process), which is known as high energy consuming and large CO2 emitting process. Herein, the copper nanodendrites (Cu NDs) grown along with {200} facet as an efficient NtRR catalyst has been successfully fabricated and investigated. It exhibited high faradaic efficiency of 97% at low potential (-0.3 V vs RHE). Furthermore, the 15NO3ˉ isotope labelling method was utilized to confirm the formation of NH3. Both experimental and theoretical studies showed that NtRR on Cu metal nanostructure is a facet dependent process. Dissociation of NO bonding is supposed to be the rate determining step as NtRR is a spontaneously reductive and protonation process for all the different facets of Cu. Density functional theory (DFT) calculations revealed that Cu{200} and Cu{220} offer lower activation energy for dissociation of NO compared to that of Cu{111}.

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Congratulations, 
Shivaraj on successfully defending his dissertation and becoming Dr. Shivaraj B. Patil!

Dr. Shivaraj B. Patil received his PhD’s degree from Tunghai University, Taiwan in 2021. In the three years of his PhD life, He focuses on electrocatalytic catalysis and energy storage systems. He has published five first-author papers on JMCA, Small, PCCP and ACS AMI, etc. The Di-Yan Lab wishes you the very best luck in your future.

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Enhanced N2 Affinity of 1T-MoS2 with Unique Pseudo Six-membered Ring Consisting of N—Li—S—Mo—S—Mo for High Ambient Ammonia Electrosynthesis Performance

Shivaraj B. Patil,1#Hung-Lung Chou,2# Yu-Mei Chen,1 Shang-Hsien Hsieh,3 Chia-Hao Chen,3 Chia-Che Chang,1 Shin-Ren Li,1 Yi-Cheng Lee,1 Ying-Sheng Lin,1 Hsin Li,1 Yuan Jay Chang,1 Ying-Huang Lai,1 Di-Yan Wang1*

Accepted by J. Mater. Chem. A

The Haber–Bosch process is widely used to convert atmospheric nitrogen (N2) into ammonia (NH3). However, the extreme reaction conditions and abundant carbon released by this process make it important to develop a greener NH3 production method. The electrochemical nitrogen reduction reaction (NRR) is an attractive alternative to the Haber–Bosch process. Herein, we demonstrated that molybdenum sulfide on nickel foil (1T-MoS2-Ni) with low crystallinity was an active NRR electrocatalyst. 1T-MoS2-Ni achieved a high faradaic efficiency of 27.66% for the NRR at −0.3 V (vs. RHE) in LiClO4 electrolyte. In-situ X-ray diffraction and ex-situ X-ray photoemission analyses showed that lithium ions intercalated into the 1T-MoS2 layers during the NRR.Moreover, theoretical calculations revealed the differences between six membered rings formed in the 1T-MoS2 and 2H-MoS2 systems with Li intercalation. The bond distances of d(Mo—N) and d(N—Li) of in Li-1T-MoS2 were found to be shorter than those in Li-2H-MoS2, resulting in a lower energy barrier of N2 fixation and higher NRR activity. Therefore, 1T-MoS2-Ni is promising as a scalable and low-cost NRR electrocatalyst with lower power consumption and carbon emission than the Haber–Bosch process.

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