CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yong-Chao Zhang,Caidi Han,Jian Gao,Jinting Wu,Xiao-Dong Zhu,Ji-Jun Zou
Electrocatalytic water splitting has received widespread attention. However, due to the slow reaction kinetics and complex electron transfer process, the oxygen evolution reaction (OER) occurring at the anode has become a bottleneck. Herein, the metal-defective Co 3- x O 4 was selected as the electron-acceptor carrier and Co 3- x O 4 /NiO was synthesized by a simple two-step method. The results show that Co 3- x O 4 /NiO has a low overpotential of 240 mV and 320 mV at 10 mA·cm −2 and 100 mA·cm −2 , a low Tafel slope of 64 mV/dec, and the electrochemical surface area (ECSA) of Co 3- x O 4 /NiO is as high as 1033.3 cm 2 . Moreover, the decrease in activity after the 60 h stability testing is negligible. Combining experiments and theoretical calculations, the high activity and stability of Co 3- x O 4 /NiO is attributed to the tunable electronic structure, and more electrons are transferred from NiO to Co 3- x O 4 which leads to the in-situ generation of more Ni 3+ as active sites. The Co 3- x O 4 /NiO with abundant of Ni 3+ can effectively regulate the oxygen-containing intermediates (OH*, O* and OOH*) with appropriate binding energy, reduce Gibbs free energy change of rate-limiting step, and accelerate OER reaction kinetics. This work provides an efficient strategy to generate and stabilize Ni 3+ active sites and confirms the key catalytic role of Ni 3+ in the OER process.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Ying Liu,Pu Liu,Wei Qin,Xiaoju Wu,Guowei Yang
To explore the surface state of electrocatalysts , herein we developed a surface laser modification (pulsed laser ablation , PLA) approach for the fabrication of NiCo 2 O 4-δ with substantial inner oxygen vacancies (Vo ·· ) and higher exterior Ni 3+ /Ni 2+ ratio. The separated NiCo 2 O 4 nanoplates were transformed to cross-linked NiCo 2 O 4-δ nanostructure through PLA strategy. As compare with the primordial NiCo 2 O 4 produce, the laser-modificated NiCo 2 O 4-δ exhibits higher capacitance, lower overpotential and better electrocatalytic performance. The first-principles calculation proves that the additional energy level is introduced between the valence band and conduction band of L-NiCo 2 O 4-δ . The additional energy level not only benefits the hopping of electrons, but also inhibits the recombination of electron-hole pairs. The X-ray photoelectron spectrum (XPS) confirms that the active sites of the electrocatalytic reaction are Vo ·· , suggesting that the electron structure of catalyst could be adjusted by PLA. The high electrocatalytic activity of laser-modificated NiCo 2 O 4-δ could be ascribed to the synergistic effect of increased number of inner Vo ·· , higher electrochemically active surface area , and dominated Ni oct . Our findings might inspire new thoughts on the tuning the surface state and electronic structure of electrocatalyst.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Wenjing Wang,Haobo Shi,Haoyang Huang,Hongying Liu,Chengxiang Li,Yongsheng Han
Hydrogen peroxide is a green oxidizing chemical with wide applications in industry. Its production heavily relies on the industrial anthraquinone process, which involves a large number of organic pollutants, challenging green and sustainable development. The recently developed pulsed electrochemical approach holds great potential for the green synthesis of hydrogen peroxide, but it is limited by the absence of highly efficient catalysts. Here, we report a strategy to improve the performance of Ni3S2 catalyst by tuning the content of Ni3+ species. The Ni3S2 catalyst exhibits good performance in oxygen evolution and oxygen reduction processes at the same time, leading to the formation of hydrogen peroxide. The enrichment of Ni3+ ensures the adsorption of reaction intermediates *O, *OH, and *OOH and promotes electron transfer during the reaction, thus facilitating hydrogen peroxide generation. By tuning the Ni3+ ratio in the Ni3S2 catalyst, the productivity of hydrogen peroxide was enhanced. The prepared hydrogen peroxide was used for propylene oxidation, resulting in pH-dependent products. This study highlights the significance of the design and rational synthesis of electrochemical catalysts for synthesizing hydrogen peroxide, which may be used for the electrochemical synthesis of chemicals.
研究领域:
材料科学
·
电化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2021
·Vol. 45
·期 10
·15544-15556
·
IF 5.164
Xuerui Yi,Fengxiang Yin,Xiaobo He,Guoru Li
Summary Water splitting driven by renewable energy represents a sustainable way to store clean energy. However, its efficiency is limited by the kinetically sluggish oxygen evolution reaction (OER), calling for highly active catalysts to accelerate the reaction rate. Herein, NiO is reduced by cellulose through a hydrothermal method to obtain the highly active OER catalysts. The obtained cellulose-partially-reduced-NiO (CL-prNiO) shows a hybrid structure, composed of 3.6 wt.% face-centered cubic (fcc) Ni and 96.4 wt.% rock salt structured NiO with highly disordered interface. The CL-prNiO delivers a current density of 10 mA cm −2 with an overpotential of 288 mV, which is comparable to the commercial RuO 2 and outperforms many of the recently reported Ni-NiO based OER catalysts. As benefited from the hybrid and disordered structure, CL-prNiO shows great ability of converting Ni 2+ to Ni 3+ at a potential prior to the OER onset. The in situ generated Ni 3+ species can activate the lattice oxygen in the unreduced NiO of CL-prNiO, significantly boosting the OER activity.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2024
·Vol. 16
·期 36
·16933-16941
·
IF 5.8
Xinyu Feng,Siwen Zhang,Jiazhuo Li,Yingfang Hu,Rongyuan Ge,Yaowen Shi,Yali Yao,Bosi Yin,Tianyi Ma
Ni3(NO3)2(OH)4 has a high theoretical specific capacitance, low cost, and environmental friendliness, making it a promising electrode material. Specifically, Ni3(NO3)2(OH)4 electrodes have a larger layer spacing (c = 6.898 Å) than Ni(OH)2 electrodes since NO3− has a much larger ionic radius than OH−. The larger layer spacing stores more electrolyte ions, significantly improving the electrochemical activity of the electrodes. Additionally, the interlayer NO3− can enhance the structural stability of Ni3(NO3)2(OH)4. However, since Ni3(NO3)2(OH)4 has a higher molar mass than Ni(OH)2, it has a lower theoretical specific capacity. Consequently, Ni3(NO3)2(OH)4 has not been used in zinc-based alkaline batteries. Studies showed that doping could enhance the electrochemical performance of electrode materials. Therefore, this study used a simple solvothermal reaction to synthesize yttrium-doped Ni3(NO3)2(OH)4 (Y-Ni3(NO3)2(OH)4), assembling a Y-Ni3(NO3)2(OH)4//Zn battery for electrochemical testing. Y-Ni3(NO3)2(OH)4 served as the cathode in the battery. The analysis of Y-Ni3(NO3)2(OH)4 showed that yttrium (Y) doping increased the specific surface area and pore size of Ni3(NO3)2(OH)4 significantly. The increased specific surface area improved the active material utilization, and the abundant mesopores facilitated OH− transport, substantially enhancing the battery's specific capacity and energy density. Ultimately, the specific discharge capacity of the advanced Y-Ni3(NO3)2(OH)4//Zn battery reached 177.97 mA h g−1 at a current density of 4 A g−1, nearly doubling the capacity of the earlier Ni3(NO3)2(OH)4//Zn battery (103.59 mA h g−1).
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Xiaotian Zhang,Zipeng Jin,Kunting Li,Yisheng Hu,Lei Xu,Baiyan Li
Despite their high surface area, remarkable porosity, and efficient charge transfer mechanisms, conductive MOFs have found limited utilization within the domain of photocatalysis. In this study, we synthesized a cutting-edge S-type Ni3(HITP)2/TiO2 heterojunction photocatalyst exhibiting outstanding light harvesting and prolonged lifetime of photogenerated electrons through an in situ synthesis approach. Compared with TiO2, the composite materials not only significantly increase the specific surface area by 4.07 times but also expand the visible light absorption edge from 400 to 1100 nm. The hydrogen production rate of Ti/Ni-3 reached 4.927 mmol·g–1·h–1, which is 4.51 times that of TiO2. The S-type interface charge transfer pathway of the Ni3(HITP)2/TiO2 composite material was inferred by band structure, in situ XPS, SPV, and free radical capture, which improves charge separation and extends the carrier lifetime to undergo directional migration driven by an IEF. This is the main reason for the improved photocatalytic performance of Ni3(HITP)2/TiO2 composite materials.
研究领域:
材料科学
·
光化学
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science Bulletin
·
2020
·
IF 9.511
Weiwei Zhao,Tiantian Chen,Weikang Wang,Beibei Jin,Jiali Peng,Shuaihang Bi,Mengyue Jiang,Shujuan Liu,Qiang Zhao,Wei Huang
The flexible transparent supercapacitors have been considered as one of the key energy-storage components to power the smart portable electronic devices. However, it is still a challenge to explore flexible transparent capacitive electrodes with high rate capability. Herein, conductive Ni 3 (HITP) 2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) thin films are adopted as capacitive electrodes in flexible transparent supercapacitors. The Ni 3 (HITP) 2 electrode possesses the excellent optoelectronic property with optical transmittance ( T ) of 78.4% and sheet resistance ( R s ) of 51.3 Ω sq –1 , remarkable areal capacitance ( C A ) of 1.63 mF cm −2 and highest scan rate up to 5000 mV s −1 . The asymmetric Ni 3 (HITP) 2 //PEDOT:PSS supercapacitor ( T = 61%) yields a high C A of 1.06 mF cm −2 at 3 μA cm −2 , which maintains 77.4% as the current density increases by 50 folds. The remarkable rate capability is ascribed to the collaborative advantages of low diffusion resistance and high ion accessibility, resulting from the intrinsic conductivity, short oriented pores and large specific areas of Ni 3 (HITP) 2 films.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Yongjiao Sun,Jun Li,Yuchen Hou,Bingliang Wang,Wendong Zhang,Koichi Suematsu,Lin Chen,Jie Hu
Electrically conductive metal-organic frameworks (EC-MOFs) exhibit significant potential application as sensing materials for chemical resistance gas sensors. Herein, we developed a flexible gas sensor based on Ni 3 (HITP) 2 nanosheets co-functionalized with noble metal nanoparticles (NPs) and WS 2 quantum dots (QDs) for NO 2 detection at room temperature. The gas sensing performance was regulated by optimizing the metal species and loading ratios of WS 2 QDs. The measured results revealed that Au NPs and 2 mol% WS 2 achieved the most effective enhancement for NO 2 sensing performance. Therefore, Au NPs was selected to optimize WS 2 -2/Ni 3 (HITP) 2 sensor for further improving the sensing properties. A unique hierarchical structure based on gas sensor (Au 3 @WS 2 -2/Ni 3 (HITP) 2 sensor) enables high response (14.73 % to 5 ppm NO 2 ), rapid response/recovery time (97 s/110 s), good selectivity, anti-humidity, repeatability, long-term stability as well as flexibility at room temperature. Furthermore, density functional theory (DFT) and band theory were employed to comprehend adsorption energies and the electronic structures at atomic scale, elucidating the intrinsic correlation between NO 2 adsorption behavior and Ni 3 (HITP) 2 surface and the sensitization mechanism of heterostructures. These findings provide novel insights for designing high-performance NO 2 gas sensors worked at room temperature and guidance for EC-MOFs sensing mechanism.
研究领域:
材料科学
·
化学传感
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2024
·Vol. 30
·期 4
·2375-2385
·
IF 2.4
Cao Lin-an,Wei Min,Guo Xin,Wang Dailian,Chen Lu,Guo Jing
Ni 3 (HITP) 2 (HITP: 2,3,6,7,10,11-hexaiminotriphenylene) is a very typical 2D electrically conductive metal–organic framework (EC-MOF) material with great promising as active materials in electronic devices. Gas–liquid interface self-assembly is a common method of processing free-standing thin films for this EC-MOF. Owing to the different contact environment during growth process, Ni 3 (HITP) 2 film prepared by gas–liquid interface method has different morphology for up-side surface exposed to air and down-side surface infiltrated in solution. However, the asymmetrical morphology of Ni 3 (HITP) 2 film and its influence on sensing performance have never been implemented. In this work, gas–liquid interface self-assembly method is used to obtain an asymmetrical Ni 3 (HITP) 2 nanofilm in surface morphology with a flat up-side surface and an island-like down-side surface. The surface morphology of as-prepared film has a remarkable influence on the glucose sensing property. The island-like structure for down-side surface film exhibits more excellent glucose sensing performance because of its abundant crystal defect which play an important role in enhancing glucose catalytic oxidation capacity. Graphical abstract
研究领域:
材料科学
·
纳米技术
·
传感器
·
电化学
✓ 已验证
DOI
高影响因子
Materials Today Energy
·
2023
·
IF 9.3
Taotao Hu,Hongming Hou,Jin Peng,Qiaofeng Wu,Jialong He,Hua Yu,Rui Liu,Tian Hou,Xiangqing Zhou,Meng Zhang,Xiaolong Zhang,Xinchun Yang,Yuanmiao Sun,Xuanhua Li,Yang Bai
NiO x plays a vital role in fabricating efficient and stable inverted perovskite solar cells (PSCs). However, the relatively low conductivity and inefficient hole extraction of NiO x hole transport layer (HTL) due to the low Ni 3+ /Ni 2+ ratio limit its use in high-efficiency PSCs. Here, we report a facile strategy to remarkably enhance the electrical conductivity and hole extraction capability of NiO x HTL by simply introducing the small molecule 4- tert -butylpyridine ( t BP) as additive in the NiO x precursor solution. It is revealed that the t BP efficient improves the charge selectivity of the NiO x interface, inducing the preferable p-type carrier concentration on the surface. Consequently, more oxygen is involved in the process of Ni 2+ to Ni 3+ conversion, and the resulting t BP: NiO x HTL exhibits significantly enhanced hole extraction and transport property. In addition, a thin layer of LiF is applied to passivate the surface of NiO x , which enables improved hole migration ability by the dipole effect of LiF and reduced trap state density of the surface. The inverted PSCs (0.16 cm 2 ) fabricated with t BP: NiO x HTL delivers an enhanced efficiency of 20.2% relative to the control devices (17.5%). t BP: NiO x devices with a large area of 1 cm 2 are also demonstrated, which achieve a decent efficiency of 16% with excellent long-term stability.
研究领域:
材料科学
·
能源技术
·
光伏器件
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Jiajia Zhang,Fang Cui,Qinghai Ma,Tieyu Cui
Low-cost and eco-friendly Ni/NiO heterojunctions have been theoretically proven to be the ideal candidate for stepwise electrocatalysis of alkaline hydrogen evolution reaction, attributed to the preferred OH ad adsorption by incompletely filled d orbitals of NiO phase and favorable H ad adsorption energy of Ni phase. Nevertheless, most Ni/NiO compounds reported so far fail to exhibit excellent catalytic activity, possibly due to the lack of efficient electron transport, limited interfacial active sites, and unregulated Ni n+ ratios. To address the above bottlenecks, herein, the ultrasmall Ni/NiO x @C nanocapsules (<5 nm) are directly constructed by graphitization of four-layer Ni-based coordination polymers at record low temperatures of 400 °C. Ascribed to the accelerated electron and mass transfer by the carbon nano-onions coated around Ni/NiO x heterojunctions, the extreme rise in interfaces and Ni 3+ defects with t6 2ge1 g electronic configuration owed to the ultrasmall size, the Ni/NiO x @C nanocapsules exhibit the highest catalytic activity and the lowest overpotential of η 10 = 80 mV among various Ni/NiO materials (measured on the glassy carbon electrode). This work not only constructs an industrialized high-efficiency electrocatalyst toward alkaline HER, but also provides a novel strategy for the constant-scale preparation of multicomponent transition metals-based nanocrystals below 4 nm.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Hongliang Dai,Pengjie Zhou,Shenming Yang,Lili Yang,Hongye Bai,Cui Dai,Guohai Xu,Weiqiang Fan
Electrocatalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is significant for the sustainable production of value-added chemicals. Active sites of catalysts could enhance the activity and selectivity of the HMF oxidation reaction (HMFOR), but the self-healing ability of active sites has been commonly ignored. In this work, Co(OH)2/Ni-MOF was successfully fabricated for efficient oxidation of HMF to FDCA under mild conditions. Electrochemical and cyclic stability experiments demonstrated the high self-healing properties of the dual active sites (Co3+/Ni3+). So, the retention rate of FDCA yield can still reach 98.5%, even after 90 days. HMFOR was further coupled with 4-nitrophenol hydrogenation, which promotes the yield and Faradaic efficiency of FDCA to about 100%. Therefore, this study explores the self-healing properties of species and provides new insights for designing efficient catalysts.
研究领域:
电化学
·
催化
·
可持续化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）