Inorganics
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2022
·Vol. 10
·期 3
·29
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IF 3.149
Van Thi Thanh Ho,Dung Hung Chau,Khang Quang Bui,Ngan Thi Thanh Nguyen,Thi Kim Ngan Tran,Long Giang Bach,Son Nguyen Truong
TiO2-based photocatalysts still have some limitations such as large bandgap and low surface area, leading to low efficiency in the photocatalytic degradation of VOCs and limiting it to use in sunlight. Here we report that the nanostructured Ir-doped TiO2as an efficient photocatalyst generates an excellent risk-reduction material of gaseous toluene. We have succeeded in developing a nanostructured Ir-dopedTiO2and initially found that excellent efficient photocatalytic VOC decomposition can be achieved in our materials The nanostructured Ir-dopedTiO2was synthesized by a one pot, low temperature hydrothermal process with different ratios of Ir doped into theTiO2. It exhibited a high surface area, uniformly spherical morphology of 10–15 nm. Its activity for the photocatalytic degradation of gaseous toluene exhibited up to 97.5% under UV light. This enhancement could be explained by iridium doping which created a high concentration oxygen vacancy and changed the recombination rate of the photogenerated charge carriers. More generally, our study indicates a strategic way to develop the novel nanostructured material for numerous applications.Keywords:photocatalysts;Ir-doped TiO2;VOCs;toluene
研究领域:
材料科学
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环境科学
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DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2018
·Vol. 18
·期 10
·6928-6933
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IF 1.354
Huynh Tai Thien,Van Nguyen At,Pham Hau Quoc,Vinh Nguyen Huu,Bach Long Giang,Thanh Ho Van Thi
Non-carbon materials are considered as the promising candidates for carbon-based catalyst support to increase the durability of proton exchange membrane fuel cells (PEMFCs). Due to the high stability and good electrical conductivity of TiO2, M-doped TiO2 (M is
transition metals: Mo, Ru, V, W) is an emerging candidate for Pt nanoparticles support on the cathode side of PEMFCs. In this research, the synthesis mechanism of Ti0.7Ir0.3O2 nanostructure by the one-step hydrothermal method at low temperature was studied.
We found that by only controlling the pH of the precursor solution, Ti0.7Ir0.3O2 can be synthesized with different morphology and phase selection without any formation of mixed oxides. In particular, Ti0.7Ir0.3O2 nanostructure
synthesized at pH = 0 exhibited concomitant anatase, brookite, and rutile phases. The spherical particles of diameter 20–40 nm, cubic particles of 30–50 nm in side-length and rod-like particles with 70 nm in length and 20 nm in diameter represented the anatase, brookite, and rutile
phases respectively. At a pH value of 1 or 2, the majority of spherical nanoparticles were homogeneous at 15–20 nm in diameter. It was observed that the electronic conductivity of novel Ti0.7Ir0.3O2 nanostructure was significantly higher than that of
the undoped TiO2. Thus the promising properties of this new nanostructure open a new path to the much-needed fuel cell applications.
研究领域:
材料科学
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燃料电池
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化学工程
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DOI
PubMed
高影响因子
DALTON TRANSACTIONS
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2022
·Vol. 51
·期 22
·8832-8839
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IF 4.569
Yihao Gao,Jie Bai,Tianning Zhou,Yaqiong Gong
In recent years, Co-based metal–organic frameworks (Co-MOFs) have received significant research interest because of their large specific surface area, high porosity, tunable structure and topological flexibility. However, their comparatively weak electrical conductivity and inferior stability drastically restrict the application of Co-MOFs in the synthesis of electrocatalysts. In this study, ZIF-67 was grown on nickel foam by a room temperature soaking method, and then Ir–Co(OH)2@ZIF-67/NF was assembled by a hydrothermal method. The prepared Ir–Co(OH)2@ZIF-67/NF nanosheets exhibit remarkable conductivity, larger electrochemical active surface area and wider electron transport channels. Only ultralow overpotentials of 198 mV, 263 mV, and 300 mV were needed for Ir–Co(OH)2@ZIF-67/NF to reach the current densities of 10 mA cm−2, 50 mA cm−2, 100 mA cm−2, meanwhile, no obvious degradation of the current density at 10 mA cm−2 was observed for about 16 h. This work may provide a promising strategy for developing high-performance MOF-derived materials as electrocatalysts for the OER under alkaline conditions.
研究领域:
材料科学
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电化学
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PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Kangwang Wang,Longfu Li,Peifeng Yu,Nannan Tang,Lingyong Zeng,Kuan Li,Chao Zhang,Rui Chen,Zaichen Xiang,Huichao Wang,Yongqing Cai,Kai Yan,Huixia Luo
Topological semimetals with protected surface states mark a new paradigm of research beyond the early landmarks of band-structure engineering, allowing fabrication of efficient catalyst to harness the rich metallic surface states to activate specific chemical processes. Herein, we demonstrate a facile solid-phase method for in-situ doping of Ir at the Os sites in the Os 3 Sn 7 , an alloy with topological states, which significantly improves the photocatalytic performance for the reduction of CO 2 to CO and CH 4 . Experimental evidence combined with theoretical calculations reveal that the nontrivial topological surface states greatly accelerate charge-separation/electron-enrichment and adsorption/activation of CO 2 molecules, rendering highly efficient reaction channels to stimulate the formation of *COOH and *CO, as well CHO*. This work shows the promise of achieving high photocatalytic performances with synthesizing topological catalysts and provides hints on the design of novel topological catalysts with superior photoactivity towards the CO 2 reduction reaction.
研究领域:
材料科学
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催化化学
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环境科学
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高影响因子
Journal of Materials Chemistry A
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2020
·Vol. 8
·期 19
·9871-9881
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IF 11.301
Ronglei Fan,Qiaoqiao Mu,Zhihe Wei,Yang Peng,Mingrong Shen
Developing cost-effective bifunctional electrocatalysts with low kinetic overpotential and superior stability for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial to build a water splitting system for advancing the production of hydrogen fuel. Herein, we report a bifunctional catalyst by doping atomic Ir into a NiCo layered double hydroxide (LDH) using a facile atmospheric solvothermal method and subsequent spontaneous galvanic displacement. The as-synthesized atomic Ir-doped NiCo LDH exhibits much better durability for over 200 h than the NiCo LDH with the loading of Ir nanoparticles, due to the fine doping of atomic Ir into the crystal lattice of LDH. Benefiting from the synergistic effects in the HER/OER processes, as well as the large electrochemically active surface area and the improved electrical conductivity, the atomic Ir-doped NiCo LDH couple results in an unprecedented performance for overall water splitting with a low cell voltage of 1.45 V at 10 mA cm−2 in a 1.0 M KOH electrolyte. Finally, a practical solar-driven water splitting system with a solar-to-hydrogen efficiency of 14.8% is demonstrated, outperforming the state-of-the-art analogous systems based on ordinary Si solar cells.
研究领域:
材料科学
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电催化
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可再生能源
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DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
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2024
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IF 1.4
Chaoran Zhou,Zhixian Liang,Hao Qiu,Shanshan Jiang,Wei Wang,Chao Su
Solid oxide fuel cells (SOFCs) as highly effective energy conversation devices have gained substantial recognition and research interest. The electrochemical properties of the traditional SOFCs are restricted by the sluggish reaction kinetics for the cathode material when lowering the operation temperature to below 600°C. In addition, the stability of the cathode at reduced temperatures is also a big challenge for the widely popularization of SOFC technology. Achieving high activities and stable ORR in the cathode is crucial for the development of SOFCs. The doping active metal method has been demonstrated as an effective approach to optimize the phase structure and improve the ORR activity of the cathode. Herein, we successfully develop an Ir-doped SrCoO 3 − δ (SrCo 0.98 Ir 0.02 O 3 − δ , SCI) cathode for SOFCs. SCI exhibits a low area-specific resistance (ASR) of 0.057 Ω cm 2 at 650°C, ~ 44% lower than 0.102 Ω cm 2 of Ir-free SrCoO 3 − δ . The Ni–Sm 0.2 Ce 0.8 O 1.90 (SDC) anode-supported fuel cell with SDC electrolyte and SCI cathode obtains an excellent output performance (e.g., 1,128 mW cm −2 at 650°C). The desired results underscore the feasibility of the Ir-doping strategy as an optimized method for the exploitation of advancing cathode in SOFCs.
研究领域:
材料科学
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能源技术
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2021
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IF 8.128
Kai Peng,Weiqi Zhang,Narayanamoorthy Bhuvanendran,Qiang Ma,Qian Xu,Lei Xing,Lindiwe Khotseng,Huaneng Su
Pt-based alloy nanomaterials with nanodendrites (NDs) structures are efficient electrocatalysts for methanol oxidation reaction (MOR), however their durability is greatly limited by the issue of transition metals dissolution. In this work, a facile trace Ir-doping strategy was proposed to fabricate Ir-PtZn and Ir-PtCu alloy NDs catalysts in aqueous medium, which significantly improved the electrocatalytic activity and durability for MOR. The as-prepared Ir-PtZn/Cu NDs catalysts showed distinct dendrites structures with the averaged diameter of 4.1 nm, and trace Ir doping subsequently improved the utilization of Pt atoms and promoted the oxidation efficiency of methanol. The electrochemical characterizations further demonstrated that the obtained Ir-PtZn/Cu NDs possessed enhanced mass activities of nearly 1.23 and 1.28-fold higher than those of undoped PtZn and PtCu, and approximately 2.35 and 2.67-fold higher than that of Pt/C in acid medium. More excitingly, after long-term durability test, the proposed Ir-PtZn and Ir-PtCu NDs still retained about 88.9% and 91.6% of its initial mass activities, which further highlights the key role of Ir-doping in determining catalyst performance. This work suggests that trace Ir-doping engineering could be a promising way to develop advanced electrocatalysts toward MOR for direct methanol fuel cell (DMFC) applications.
研究领域:
材料科学
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电化学
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燃料电池
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
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2022
·Vol. 46
·期 13
·19221-19232
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IF 4.672
Vi Thuy Thi Phan,Toan Minh Pham,Hau Quoc Pham,Tai Thien Huynh,Thi Hong Tham Nguyen,Van Thi Thanh Ho
Summary Highly stable and cost-effective electrocatalysts are of importance in regulating energy conversion efficiency and commercial feasibility of direct methanol fuel cells (DMFCs). So far, integrating transition metals into Pt-based catalysts to enhance their catalytic performances for methanol electro-oxidation reaction (MOR) at the anode of DMFCs has received significant interest. This study witnessed the first time of depositing Pt 3 Co 1 alloy nanoparticles (NPs) on robust Ti 0.9 Ir 0.1 O 2 supports utilizing a modified reduction method that used NaBH 4 as a reducing agent in the absence of surfactants or stabilizers. This novel combination not only reduces the usage of costly and easily-deactivated Pt but also significantly improves catalytic activity and poisoning tolerance for MOR. Regarding electrocatalytic performance, the onset potential and the mass activity of the Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst are ~0.1 V vs NHE and 316.16 mA/mg Pt , respectively, which are 4.5-fold lower and 1.5-fold higher than the corresponding figures for the commercial Pt/C (E-TEK) catalyst, ~0.45 vs NHE and 206.83 mA/mg Pt , indicating superior catalytic activity and CO-tolerance of the former over the latter. Furthermore, the superior anti-poisoning ability and stability of the Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst are demonstrated by its 2.2-fold higher I f /I b ratio in MOR and lower degradation rate in the 60-min chronoamperometry (CA) and 3000-cycle scanning tests than the Pt/C counterpart. These enhancements could be abscribed to synergistic influence between the Pt-Co alloy NPs and the robust Ti 0.9 Ir 0.1 O 2 support. The addition of Co into the catalyst to promote removal of Pt-poisoning species as well as the use of highly corrosion-resistant Ir-doped TiO 2 as a catalyst support play a decisive role in boosting electrochemical behaviors of the Pt 3 Co 1 / Ti 0.9 Ir 0.1 O 2 catalyst. Generally, the success of this work in synthesizing high-performance Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst could serve as groundwork for further development of TiO 2 -based material supported bimetallic catalysts for applications in the electrochemical catalysis field.
研究领域:
材料科学
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电化学催化
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高影响因子
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