SOLAR ENERGY
·
2021
·
IF 5.742
Xiaobo Chen,Yefei Zhuang,Qingyu Shen,Xiaoyu Cao,Wen Yang,Peizhi Yang
Low electrocatalytic activity and/or high charge transfer resistance of counter electrodes (CEs) in quantum-dot-sensitized solar cells (QDSSCs) are the main reasons for the low photovoltaic performance . Herein, the CoS nanoparticles are anchored on the MXene (Ti 3 C 2 T x ) via a simple in-situ hydrothermal reaction process. It is the first attempt to use the MXene/CoS as a highly electrocatalytic CE for QDSSCs . The QDSSCs with a MXene/CoS CE shows a significant enhancement in cell performances and yields a promising power conversion efficiency (PCE) of 8.09% compared with that of the QDSSCs with bare CoS (5.77%) and bare MXene (4.25%) CEs. The significant enhancement of PCE value is mainly attributed to the synergistic effects of the unique layered morphology of conductive MXene nanosheets and its cocatalysis with CoS nanoparticles. The coupling of layered MXene with small CoS nanoparticles (~15 nm) provides abundant catalytic active sites. The improved mesoporous morphology contributes a high specific surface area and fast electron transfer channels for S x 2− reduction. Consequently, the MXene/CoS nanocomposite can be utilized as an effective agent to boost up the photovoltaic performance of QDSSCs.
研究领域:
材料科学
·
能源化学
·
纳米科技
·
光伏技术
·
电化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Ao Hu,Xinhuan Lu,Dongming Cai,Haijun Pan,Run Jing,Qinghua Xia,Dan Zhou,Yongde Xia
N-doped porous carbons incorporating highly-dispersed non-noble metallic cobalt (Co) nanoparticle materials were synthesized by rapid pyrolysis of a zeolitic-type metal-organic framework (ZIF-9) and their structures, morphologies, topologies and relevant physical and chemical properties were fully measured by different characterization technologies. The resulting derived Co/CN materials were further evaluated as catalysts in nitrobenzene hydrogenation. It was found that Co/CN materials showed remarkbly catalytic activity and chemoselectivity for mild hydrogenation of nitrobenzene. Amongst the studied a series of Co/CN-x (pyrolyzed at x °C) materials, sample Co@CN-800 shows the most superior catalytic activity for hydrogenation of nitrobenzene. In particular, the catalytic conversion activity of Co@CN-800 is 100% with aniline being the sole product at 70 °C for 2 h, 27.5 times higher than that of cobalt powder (Co). It is believed that the large pore size, adsorption of nitroarenes substrate with high selectivity and strong interaction of Co nanoparticles with the doped N species can result in the high activity of Co@CN-800. This work therefore offers a cost-effective approach in developing highly efficient catalytic materials towards mild hydrogenation of nitrobenzene.
研究领域:
催化化学
·
材料科学
·
有机合成
·
纳米材料
·
环境化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Shusheng Li,Rui Kuang,Xiangzheng Kong,Xiaoli Zhu,Xubao Jiang
Highly efficient and robust electrocatalysts have been in urgent demand for oxygen evolution reaction (OER). For this purpose, high-cost carbon materials , such as graphene and carbon nanotubes , have been used as supports to metal oxides to enhance their catalytic activity . We report here a new Co 3 O 4 -based catalyst with nitrogen-doped porous carbon material as the support, prepared by pyrolysis of porous polyurea (PU) with Co(NO 3 ) 2 immobilized on its surface. To this end, PU was first synthesized, without any additive, through a very simple one-step precipitation polymerization of toluene diisocyanate in a binary mixture of H 2 O-acetone at room temperature . By immersing PU in an aqueous solution of Co(NO 3 ) 2 at room temperature, a cobalt coordinated polymer composite , Co(NO 3 ) 2 /PU, was obtained, which was heated at 500 °C in air for 2 h to get a hybrid, Co 3 O 4 /NC, consisting of Co 3 O 4 nanocrystals and sp 2 -hybridized N-doped carbon. Using this Co 3 O 4 /NC as a catalyst in OER, a current density of 10 mA·cm −2 was readily achieved with a low overpotential of 293 mV with a Tafel slope of 87 mV·dec −1 , a high catalytic activity. This high performance was well retained after 1000 recycled uses, demonstrating its good durability. This work provides therefore a facile yet simple pathway to fabrication of a new transition metal oxides-based N-doped carbon catalyst for OER with high performance.
研究领域:
材料科学
·
电化学
·
催化化学
·
能源材料
·
纳米科技
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 3
·2077-2086
·
IF 2.599
Li Jingwei,Xu Weiming,Zhou Dan,Luo Jiaxian,Zhang Dawei,Xu Peiman,Wei Licheng,Yuan Dingsheng
Low-cost and highly active water oxidation electrocatalysts are increasingly demanded to improve the efficiency of water splitting. Herein, for the first time, we developed a facile strategy to design a three-dimensional flower-like cobalt nickel phosphate as such an electrocatalyst. The cobalt nickel phosphate was directly supported on Ni foam ((Co 0.5 Ni 0.5 ) 3 (PO 4 ) 2 /Ni) via a simple two-step hydrothermal method.
This method offers several advantages including low cost, facile synthesis and binder-free. Benefiting from its three-dimensional flower-like nanostructure with a big specific surface, high conductivity and the synergic effect of metal ions are the as-synthesized (Co 0.5 Ni 0.5 ) 3 (PO 4 ) 2 /Ni reveals excellent oxygen evolution reaction activity in alkaline electrolyte. It exhibits a low overpotential of 273 mV to reach a current density of 10 mA cm −2 and a Tafel slope of 59.3 mV dec −1 in 1.0 mol L −1 KOH. Notably, the (Co 0.5 Ni 0.5 ) 3 (PO 4 ) 2 /Ni also operates efficiently in 30 wt% KOH, capable of affording an anodic current of 10 mA cm −2 at a lower overpotential of 246 mV and retains its catalytic performance for at least 30 h.
研究领域:
材料科学
·
电化学
·
能源化学
·
纳米材料
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Hanwei Zhang,Xuri Wang,Ahmad Naveed,Tianyi Zeng,Xiaoyun Zhang,Hancheng Shi,Mingru Su,Aichun Dou,Yu Zhou,Yunjian Liu
Nickel-rich cathode materials are widely used for electronic devices because of their high capacity and rate performance. However, structural deterioration after long-term cycling leads to a significant decline in capacity and cycle life. In this work, the effects of three different cations doping on the structural stability and electrochemical performance of Ni-rich cathode materials were investigated. XRD characterization reveals that doped cation leads to broadening of the distance between Li layers and inhibiting Li + /Ni 2+ mixing arrangement. Compared with Na + and K + , the high valence Mg 2+ provides a stronger Mg-O bond, which can effectively restrain the undesired phase transition and sustain the ordered structure. Electrochemical tests demonstrate that NCA with Mg doping has better cycle stability and rate performance than Na and K. The capacity retention rate of NCA with 1% Mg doping is 87.7% after 200 cycles at 1C, and it can still provide a specific capacity of 146.8 mAh g −1 at a high rate of 5C.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 25
·19241-19247
·
IF 3.84
Lingyun Guo,Qiang Ru,Xiong Song,Shejun Hu,Yudi Mo
Herein, we report mesoporous ZnCo2O4 microspheres fabricated by a facile hydrothermal method followed by pyrolysis of a Zn0.33Co0.67CO3 precursor. The obtained ZnCo2O4 microspheres were made up of closely packed primary nanoparticles with a diameter of about 30 nm and a large number of pores that were sized between 10 to 40 nm, which results in a high BET surface area of 39.52 m2 g−1. The large surface area permits a high interfacial contact area with the electrolyte and provides more locations and channels for fast Li+ insertion/extraction into the electrode material. The porous structure may not only be beneficial for Li+ ions to diffuse efficiently to active material with less resistance but also to buffer the volume expansion during the discharging/charging processes. When used as an anode material, the specific capacity was maintained at a high value of 1256 mA h g−1 after 100 cycles at a current density of 100 mA g−1, which is about 3.4 times larger than that of the commercial graphite electrode (372 mA h g−1). More interestingly, a reversible capacity as high as 774 mA h g−1 could be retained at a high current density of 1000 mA g−1 after 200 cycles, which indicates that the mesoporous ZnCo2O4 microspheres had excellent cycling performance at a high current density for use as anode materials for lithium-ion batteries (LIBs).
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Kang An,Siran Zhang,Hong Wang,Ningyan Li,Ziyang Zhang,Yuan Liu
Direct hydrogenation of CO 2 into ethanol has been considered as an up-and-coming way to achieve CO 2 utilization. Ethanol can be generated by reverse water gas shift as well as CO hydrogenation over Co-based catalysts, where the regulation of Co 0 − Co δ+ is critical. Herein, we designed a supported Co-based catalyst doped with gallium, which was derived from Co-Al-O spinel precursor to facilitate synergistic catalyzing for CO 2 -to-ethanol transformation. The selectivity of ethanol reached 20.1 % in a continuous flow fixed micro-reactor over reduced CoGa 1.0 Al 1.0 O 4 /SiO 2 catalyst at 270 °C and 3.0 MPa. Results of characterization show that the existence of the strong interaction between Ga oxide and cobalt induced the configuration of Co 0 − Co δ+ active pairs, which promotes the process of ethanol synthesis by coupling the dissociation (CH x *)/non-dissociation (CO*) of the intermediates. The strategy by tuning the interaction between cobalt and gallium and/or aluminum oxide brings an avenue to tailor Co 0 − Co δ+ active pairs for the hydrogenation of CO and CO 2 .
研究领域:
催化化学
·
能源化学
·
材料化学
·
环境化学
·
工业催化
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 15
·6003-6009
·
IF 3.288
Yuhang Jiang,Qiuwan Shen,Shian Li,Guogang Yang,Naibao Huang
B-site cobalt-doped perovskite oxide BaNiO3 oxygen sorbents have been synthesized by an EDTA sol–gel method and further applied for producing oxygen. BaCoxNi1−xO3−δ oxygen sorbents were characterized by scanning electron microscopy (SEM) and cyclic oxygen adsorption/desorption experiments. Results showed that BaCo0.6Ni0.4O3−δ features higher production amounts of oxygen among the candidates. The operating factors of oxygen releasing performance were investigated in detail including adsorption temperature, desorption temperature, adsorption time, CO2 flow rate and CO2 partial pressure. It was concluded that the temperature and CO2 flow rate are the main reasons affecting the performance of perovskite oxygen sorbents. The optimal operating parameters of oxygen releasing performance for BaCo0.6Ni0.4O3−δ were as follows: adsorption temperature was 850 °C, desorption temperature was 850 °C, air adsorption time was 30 min, CO2 flow was 200 ml min−1 and the ratio of CO2/N2 was 100 : 0. The oxygen production amount of BaCo0.6Ni0.4O3−δ was 49.5 mg g−1 under the optimal reaction conditions. Finally, multiple cycles demonstrated that BaCo0.6Ni0.4O3−δ displays higher stability and regeneration capacity, which is the key factor providing a stable O2/CO2 gas stream for oxyfuel combustion application.
研究领域:
材料科学
·
无机化学
·
能源化学
·
化学工程
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 27
·14278-14285
·
IF 8.867
Haibo Tang,Xinlong Tian,Junming Luo,Jianhuang Zeng,Yingwei Li,Huiyu Song,Shijun Liao
Transition metal nitrides have recently attracted significant interest as electrocatalysts for the oxygen reduction reaction (ORR) owing to their low electrical resistance and good corrosion resistance. In this paper, we describe the preparation of a Nb-based binary nitride material with a porous nanogrid morphology/structure. The catalyst exhibited good catalytic activity and high stability towards oxygen reduction. We also intensively investigated the effect that doping with a second transition metal had on the performance of the catalyst. We found that the ORR activity of NbN could be enhanced significantly by enriching the d electrons of Nb through doping with a second transition metal, and that doping with cobalt resulted in the best improvement. Our optimal catalyst, Nb0.95Co0.05N, had an ORR activity ∼4.6 times that of NbN (current density @ 0.6 V vs. the RHE). XPS results revealed that Co doping increased the proportion of Nb in a low-valence state, which may be one of the most important reasons for the enhanced performance. Another important reason is the high surface area resulting from the porous nanogrid morphology. As transition metal doping is an attractive way to enhance the activity of nitride catalysts, our work may provide an effective pathway to achieve this.
研究领域:
材料科学
·
电化学
·
纳米科技
·
催化化学
·
能源材料
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2018
·Vol. 5
·期 15
·1800515
·
IF 4.834
Lingxia Zheng,Wangwang Hu,Xuwei Shu,Huajun Zheng,Xiaosheng Fang
Cobalt phosphides based materials are considered as promising electrocatalysts for the hydrogen evolution reaction (HER). The catalytic performance can be further enhanced by improving the intrinsic catalytic activity, exposing more active sites and coupling with conductive support. Herein, a novel electrocatalyst based on nitrogen doped reduced graphene oxides decorates with uniformly distributed CoP x nanoparticles with a suitable P/Co ratio ( x = 1.7) via a facile and mild condition. The optimized composite (CoP x /N-rGO) exhibits superior electrocatalytic HER activities with a low overpotential of 104 mV (at 10 mA cm −2 ), a small Tafel slope of 65 mV dec −1 , and long-term stability in the alkaline media, comparable to the performance of other HER electrocatalysts. The remarkable HER performance can be ascribed to the good electrical conductivity of rGO and extra active sites created by nitrogen doping. In addition, the ultrafine nanostructure (average particle size ≈4 nm) and well-dispersed CoP x nanoparticles also help expose more active sites for electrocatalytic reactions, largely hindering the agglomeration and exfoliation. This work provides a versatile route on the design of multifunctional composite materials for renewable energy research with low cost and high activity.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Mingyuan Chen,Yaxin Lv,Peilin Wu,Liuyan Dong,Xingquan He,Lili Cui
To obtain highly active electrocatalyst for the whole electrochemical water splitting is of importance to generate hydrogen. Co(OH) 2 is used as electrocatalyst towards OER, however, the performance can be improved further. Usually, to construct the interface and adjust the electronic environment of electrocatalysts are regarded as powerful ways to improve the activity. Herein, CeO 2 -Co(OH) 2 sheets supported on copper foam (CF) are fabricated by electrodeposition method. The morphology and the electron structure of metals are adjusted by changing the molar ratio of Co to Ce, thus, resulting in different electrocatalytic activity. The optimal hybrids of CeO 2 -Co(OH) 2 exhibits lower overpotentials of 188, 269 mV to reach 10 mA cm −2 towards HER and OER, respectively, and good stability. Notably, it is found that the electroactivity is extremely superior to that of bare CF as well as the counterparts in the literature. Also, we try to employ M(OH) 2 (M = Fe, Ni) to substitute Co(OH) 2 to investigate the effect of species of hydroxides on the electron interaction between CeO 2 and hydroxides, the XPS results indicate that Ce and Co shows stronger electron interaction compared to other two control hydroxides. As electrocatalysts for alkaline full water splitting, CeO 2 -Co(OH) 2 requires a cell voltage of 1.62 V to drive 10 mA cm −2 . Experimental results prove the advantages of the electron engineering and morphology control.
研究领域:
材料科学
·
电化学
·
能源化学
·
纳米材料
·
催化化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Cheng-Hui Zeng,Xiao-Ting Meng,Song-Song Xu,Li-Jun Han,Shengliang Zhong,Mei-Ye Jia
A rarely reported polymorphic lanthanide complex is prepared by acetylacetone (acac) tuning method. Luminescence properties of 1 are studied. Interestingly, 1 is proved to be a multifunctional material. It is a highly selective and sensitive Co 2+ sensor, among 24 species, only Co 2+ quenching the Tb 3+ centered luminescence. The possible sensing mechanism is the decomposition of 1 which induced by Co 2+ . The limit of detection (LOD) for sensing Co 2+ is as low as 330 nM, which is lower than the standard of Chinese environmental protection department. Mechanism study confirmed the luminescence quenching can be ascribed to the decomposition of 1 which induced by Co 2+ . Further investigations find 1 -Co 2+ can be applied as tunable luminescent timer, by tuning the ratio of 1 /Co 2+ . CIE coordinates of 1 -Co 2+ change regularly (has excellent linearity) from green to violet with the time increasing.
研究领域:
分析化学
·
无机化学
·
材料科学
·
环境监测
·
生物传感
·
分子探针
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）