CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xiaoge Peng,Zhikang Bao,Shijie Zhang,Yuanan Li,Lei Ding,Huaijie Shi,Jia Liu,Xing Zhong,Xiaonian Li,Jianguo Wang
Assembling two desirable half-reactions of green oxidants hydrogen peroxide (H 2 O 2 ) and ozone (O 3 ) into efficient paired electrolysis is highly valuable in terms of efficiency and environmental-friendliness. However, rational design and construction of electrocatalysts with regulable active sites for the paired electrosynthesis of green oxidants of H 2 O 2 and O 3 remain a significant challenge. Herein, A new strategy was developed for tunning the active sites of pseudo-hexagonal centers (TT, Lewis acid sites) and orthogonal centers (T, Brønsted acid sites) in Mxene layered structure niobium pentoxide (Nb 2 O 5 ) with abundant oxygen vacancy (O V ) for the paired electrolysis of 2e - oxygen reduction reaction (ORR) and electrochemical ozone production (EOP). The TT-300 and T-400 electrocatalysts exhibited outstanding electrochemical activity of 2e - ORR (H 2 O 2 selectively of 92% at 0.4 V RHE ) and EOP (gaseous ozone FE of 13% at 50 mA cm −2 ), respectively. The excellent performance was mainly attributed to the TT-300 (Lewis acid sites) and T-400 (Brønsted acid sites) with abundant O V that improve the oxygen-containing intermediates formation of OOH* and deprotonation of water. In addition, the in-situ electro-degradation of organic compounds experiments indicated that the synergistic degradation of O 3 and H 2 O 2 possessed a faster kinetic constant compared with a single electrolysis system of O 3 and H 2 O 2 . The work provides meaningful insights into the rational design and construction of advanced solid acid electrocatalysts for efficient simultaneously electrocatalytic hydrogenation and oxidation to produce green oxidants of O 3 and H 2 O 2 .
研究领域:
材料科学
·
电化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 160
·期 9
·
IF 3.1
Lin Yuda,Chen Yiheng,Qiu Liting,Zheng Shenghui
In view of the inherent pseudocapacitance, rich redox pairs (Nb 5+ /Nb 4+ and Nb 4+ /Nb 3+ ), and high lithiation potential (1.0–3.0 V vs Li/Li + ), Nb 2 O 5 is considered a promising anode material. However, the inherent low electronic conductivity of Nb 2 O 5 limits its lithium storage performance, and the rate performance after carbon modification is still unsatisfactory because the intrinsic conductivity of Nb 2 O 5 has not been substantially improved. In this experiment, taking the improvement of the intrinsic electrical conductivity of Nb 2 O 5 as the guiding ideology, we prepared F-doped Nb 2 O 5 @fluorocarbon composites (F–Nb 2 O 5 @FC) with a large number of oxygen vacancies by one-step annealing. As the anode electrode of lithium-ion batteries, the reversible specific capacity of F–Nb 2 O 5 @FC reaches 150 mA g −1 at 5 A g −1 after 1100 cycles, and the rate performance is particularly outstanding, with a capacity up to 130 mA g −1 at 16 A g −1 , which is far superior to other Nb 2 O 5 @carbon-based anode electrodes. Compared with other single conductivity sources of Nb 2 O 5 @carbon-based composites, the electrical conductivity of F–Nb 2 O 5 @FC composites is greatly improved in many aspects, including the introduction of free electrons by F − doping, the generation of oxygen vacancies, and the provision of a three-dimensional conductive network by FC. Through analytical chemistry (work function, UV–Vis diffuse reflectance spectroscopy, and EIS) and theoretical calculations, it is proved that F–Nb 2 O 5 @FC has high electrical conductivity and realizes rapid electron transfer.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2026
·Vol. 14
·期 29
·13031-13041
·
IF 7.6
Luo Qionglin,Xu Zhen,Zhang Sitian,Li Zhiling,Ren Kaixiang,Ding Can,Li Yongtao,Peng Cong,Zeng Shunqin
PEO-derived polymer electrolytes hold promise for economical, deformable lithium metal batteries with elevated energy density. Nevertheless, their deployment is constrained by insufficient Li + transport, restricted electrochemical stability, uncontrolled Li dendrite proliferation, and inferior anode cyclability. Herein, we introduce oxygen-deficient Nb 2 O 5 (Ov-Nb 2 O 5 ) into a polyethylene oxide host to fabricate an innovative solid-state electrolyte. The Ov-Nb 2 O 5 particles anchor PEO chains via Lewis acid−base interaction, forming a robust oxide−polymer interface. This interaction effectively prevents filler aggregation and reduces PEO crystallinity, yielding a homogeneous electrolyte membrane with enhanced mechanical strength. The resulting architecture accelerates Li + migration across the polymer, thereby elevating ionic transport and restraining dendrite advancement. The PEO/LiTFSI/10%Ov-Nb 2 O 5 electrolyte demonstrates a conductivity of 2.5 × 10 −4 S cm −1 alongside a Li + transference number of 0.63 at 60 ° C. Furthermore, Li-metal symmetric cells sustain steady deposition/dissolution exceeding 1500 h under 0.2 mA cm −2 . When paired with a LiFePO 4 cathode, the full cell achieves a reversible capacity of 121.4 mAh g −1 at 0.5 C and retains 91.7% of its capacity after 400 cycles. This investigation underscores an effective approach for engineering multifunctional fillers toward advanced solid electrolytes featuring rapid ion conduction and exceptional interfacial durability.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2022
·
IF 9.794
Siqi Jing,Xiaohui Yan,Taibai Li,Yige Xiong,Tao Hu,Zhongjie Wang,Xiang Ge
Supercapacitors are advantageous in terms of power density and cycle life, but their wider application is limited by self-discharge. Previous attempts for improving the stability have mainly focused on the specific component (materials, separators or electrolytes) of the device, while the feasibility for mitigating self-discharge through a general device-scale configuration is largely unknown. Herein, we report a symmetric supercapacitor with a conjugated configuration, which consists of a pair of pre-lithiated niobium oxide decorated with evenly distributed titanium dioxide, forming a Li x [(Nb 2 O 5 ):(TiO 2 ) a ] vs. Li 2-x [(Nb 2 O 5 ):(TiO 2 ) a ] conjugated configuration. The intercalation type pseudocapacitive Nb 2 O 5 are unique due to their linearly sloped charge/discharge curve like electrochemical double layer capacitances (EDLCs) while the charged ions can be inserted/extracted reversibly from the bulk like batteries . As a result, such conjugated device can store energy like conventional EDLCs, while the self-discharge process is significantly supressed. When further added with suitable amount of titanium dioxide as the stabilizer , the conjugated supercapacitor retained 74% of its energy after aging for 48 h. These results are expected to provide a general guidance for designing materials specifically for constructing conjugated supercapacitors with high initial energy density and alleviated self-discharge.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Juan Yang,Jingyi Hao,Siyu Xu,Jun Dai,Yan Wang,Xinchang Pang
In this study, Nb 2 O 5 nanorods/graphene composites (NbO NRs/GR) are prepared by one-pot alkaline hydrothermal process, utilizing the new roles of graphene oxide (GO) as the structure-directing and morphology-controlling agent for the growth of NbO NRs. Compared to blank NbO, NbO/GR composites exhibit significantly improved photocatalytic activity for 4-CP degradation under visible-light irradiation, although 4-CP and NbO do not absorb visible light themselves. The in-situ formation of surface complexes between 4-CP and NbO and the subsequent charge transfer based on LMCT mechanism can be responsible for the visible photocatalytic activity. And meanwhile, the photoelectrons transferred to GR surface from in-situ formed complex (NbO/4-CP) via NbO NRs can initiate the synergistic Cr(VI) reduction. The GR contents and NbO crystalline phase have great effects on the photocatalytic activity of NbO/GR composites toward simultaneous 4-CP degradation and Cr(VI) reduction. The amorphous NbO/GR composite with 4.0 wt% GR (NbO-400/GR-4.0%) shows the highest photocatalytic activity. The influences of various experimental conditions (including the surface fluorination of NbO/GR, the initial concentrations of 4-CP and Cr(VI), pH, reaction atmosphere, and adding radical scavengers) on the visible photocatalytic activities are investigated in detail. According to the catalytic activity, UV-vis DRS and FT-IR spectra of NbO/4-CP or NbO/GR/4-CP, and photocurrent response in aqueous 4-CP solution, the formation of the surface complex is evidenced and the visible-light catalytic mechanism based on LMCT process is proposed.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Sundaram Chandrasekaran,Na Li,Yang Zhuang,Lijun Sui,Zhizhong Xiao,Dayong Fan,Vanchiappan Aravindan,Chris Bowen,Huidan Lu,Yongping Liu
The creation of heterostructures based on non-precious metals with platinum-like hydrogen evolution reaction (HER) performance remains a challenge for hydrogen fuel technologies. Motivated by the fascinating properties of heterostructures, we establish here an effective approach to fabricate the heterostructured M−N−Ni 9 S 8 /Nb 2 O 5 ( M = Co, Fe, or Cu) catalysts using spatially separated Ni 9 S 8 nanosheet/Nb 2 O 5 nanobelts that are coupled with nitrogen (N) and metal atoms. Due to its improved intrinsic activity, interface-rich structure, abundant active sites, and large surface area the Co−N−Ni 9 S 8 /Nb 2 O 5 heterostructure achieved a low acidic HER overpotential of −171 mV at −10 mA cm −2 , thereby performing better than existing heterostructures. Moreover, for the alkaline HER, the Cu−N−Ni 9 S 8 /Nb 2 O 5 heterostructure required a low overpotential of −109 mV at −10 mA cm −2 , which is close to the performance of Pt/C catalyst. Density functional theory (DFT) predictions indicate that the local charge distribution and electronic properties at the heterointerface of Ni 9 S 8 /Nb 2 O 5 can be significantly modulated by co-doping of metals with N atoms, resulting in optimal adsorption energy and reduced water dissociation barrier; thereby accelerating the acidic and alkaline HER activity. This work, therefore, provides a new design principle to create advanced heterostructured catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 38
·18008-18018
·
IF 3.591
Onome Ejeromedoghene,Xiangyu Ma,Olayinka Oderinde,Fang Yao,Sheriff Adewuyi,Guodong Fu
A new quaternary type IV deep eutectic solvent (DES) was prepared for the synthesis of WO3/Nb2O5 complexes via a facile solvothermal route under ambient conditions. PXRD confirmed the formation of orthorhombic niobium tungsten oxide with semi-crystalline crystal phases. The SEM micrograph displayed a well aggregated and clustered particle distribution with irregular shapes, while TEM revealed a flower-shaped morphology of the materials. Furthermore, the UV-Vis measurements indicated electronic absorption in the range of 206–282 nm before irradiation with UV-light. After 5 s of irradiation, there was an instant color change from white to blue, which gradually deepened after 180 s. This color change was accompanied by a broad electronic absorption at 658 nm. Moreover, the intense photochromic material displayed fast fading within 20 min of exposure to the open air and remarkable recyclability. These observed properties could open new avenues for smart windows and color display devices.
研究领域:
材料科学
·
光化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）