JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Changming Zhang,Zhihao Liu,Yongjin Zou,Fen Xu,Lixian Sun,Zhicong Hu,Sensen Yu,Cuili Xiang
Spinel-type materials are attracting great attention as potential electrocatalysts for the hydrogen- and oxygen-evolution reactions. However, their inherent catalytic activities are not on par with those of precious-metal catalysts, and their poor stabilities continue to constrain their rapid development. In this study, we fabricated Zr-CuCo 2 S 4 nanowires and Co(OH) 2 nanosheet–nanowires using electrochemical methods, resulting in lattice defects, sulfur vacancies, and more exposed active sites that catalyze the hydrogen- and oxygen-evolution reactions. DFT calculations revealed that sulfur vacancies enhance intrinsic activity, while Zr doping reduces the energy barrier for H*–OH* adsorption, promotes the formation of additional sulfur vacancies, and modulates active-site Cu/Co valence states, which greatly enhances water-dissociation and H*-adsorption kinetics. Consequently, Zr-CuCo 2 S 4 /Co(OH) 2 requires low overpotentials of 88 and 208 mV, respectively, to support highly stable alkaline hydrogen- and oxygen-evolution reactions at 10 mA cm −2 . This study provides a rational strategy for designing low-cost spinels for green and clean energy.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Zhuang Fu,Jia-Ling Jiang,Song-Tao Dong,Miao-Cheng Yu,Lijun Zhao,Lei Wang,Shu-Hua Yao
In this study, the facile synthesis method of Bi 2 − x Zr x O 2 Se ( x = 0, 0.02, 0.04, and 0.06) ceramics using a combining the high-energy ball milling and cold pressing was reported. The effects of zirconium (Zr) doping on the microstructure and thermoelectric properties of Bi 2 O 2 Se were systematically investigated. The results indicate that the powder samples were synthesized as a single phase with no impurities. With increasing Zr content, conductivity increased from 13.49 S to 34.91 S cm −1 at 773 K. The thermal conductivity of Bi 1.98 Zr 0.02 O 2 Se was also reduced to 0.51 W m −1 K −1 . The maximum power factor (PF) value of the Bi 1.96 Zr 0.04 O 2 Se sample was 186 μW m −1 K −2 at 773 K. A peak ZT of around 0.27 was achieved for the Bi 1.96 Zr 0.04 O 2 Se sample, which is approximately 2.4 times greater than that of un-doped one (∼0.11). The results indicate that Zr-doping significantly improves the thermoelectric properties of the Bi 2 O 2 Se system.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Hui Zhang,Liping Hao,Jiyang Xie,Jianyun Cao,Wanbiao Hu
Thermoelectric materials based on SrTiO 3 are low in cost and environmentally friendly, but their performance must be further improved for practical application. In this study, we show that isovalent substitution of the B-site Ti 4+ in a La doped SrTiO 3 (LSTO) matrix is both effective in reducing thermal conductivity and improving power factor ( PF ). In brief, Zr 4+ substituted LSTO (La 0.08 Sr 0.9 Ti 1- x Zr x O 3 ; x = 0, 0.02, 0.04, and 0.06; labeled as LSTO-Zr 0.02 , LSTO-Zr 0.04 and LSTO-Zr 0.06 , respectively) are prepared by solid-state-reaction and densified in a reducing environment. The optimized LSTO-Zr 0.02 shows a 30 % increase in PF and 12 % reduction in thermal conductivity compared with that of LSTO. Particularly, the LSTO-Zr 0.06 sample with highest substitution level has the largest reduction in thermal conductivity compared to the LSTO matrix (30 %, from 8.2 to 5.6 W m −1 K −1 at 300 K). The reduction in thermal conductivity is because the Zr 4+ substitution introduces chemical impurities and lattice defects, benefiting the scattering of phonon thermal carriers. The improvement in PF after Zr substitution is attributed to the enhanced Seebeck coefficient because of the slightly reduced carrier concentration. In contrast to the B-site Ti 4+ cations, which are partially reduced to Ti 3+ under the reducing environment and contribute to electron carriers, the Zr 4+ are not reduced, resulting in lower electron carrier concentrations after Zr 4+ substitution. This isovalent substitution strategy provides a potential route for the development of high-performance thermoelectric materials based on SrTiO 3 .
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Shiwei Ma,Shiyi Chen,Huijun Ge,Tao Song,Ping Lu,Wenguo Xiang
CeO2 is a typical fluorite oxide with desirable lattice oxygen conductivity and can be applied as an active support for the Fe-based oxygen carrier in chemical looping hydrogen generation (CLHG). However, Fe2O3/CeO2 always suffers from low thermal stability and sintering. Doping foreign cations could be a proper way to improve its reactivity and cyclic stability. In this work, Zr4+ and Sm3+, with a smaller ionic radius and lower valence than Ce4+, respectively, were doped into Fe2O3/CeO2 using the co-precipitation method, and the doping effects on the reactivity and redox stability of Fe2O3/CeO2 in CLHG were investigated. Fe2O3/Ce0.6Sm0.15Zr0.25O1.925 provided the best redox reactivity, and the purity of generated hydrogen for all oxygen carriers reached nearly 100% (the detection limit of CO/CO2 was 0.01% in volume). The reactivity followed the sequence Fe2O3/Ce0.6Sm0.15Zr0.25O1.925 > Fe2O3/Ce0.8Sm0.2O1.9 > Fe2O3/Ce0.75Zr0.25O2 > Fe2O3/CeO2. However, the concentration of oxygen vacancy was ranked as Fe2O3/Ce0.8Sm0.2O1.9 > Fe2O3/Ce0.6Sm0.15Zr0.25O1.925 > Fe2O3/Ce0.75Zr0.25O2 > Fe2O3/CeO2. The Zr doping boosted the reactivity of Fe2O3/CeO2 mainly by enhancing its sintering resistance, whereas the Sm doping achieved it mainly by promoting the oxygen conductivity, whose ability to improve the thermal stability of Fe2O3/CeO2 was rather limited. Both Zr and Sm doping could suppress the outward migration of Fe cations in the particles, resulting in higher sintering resistance. Furthermore, Zr and Sm could dissolve into CeO2 for prepared Fe2O3/Ce0.6Sm0.15Zr0.25O1.925; however, the bleeding out of both dopants was observed with Sm0.5Zr0.5O1.75 formation, which could be detrimental to the redox stability of the oxygen carrier.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
Particuology
·
2021
·
IF 3.067
Suyu Zhou,Xiaojing Guo,Xi Yan,Yan Chen,Wanzhong Lang
Lithium ion sieve (LIS) has attracted great attention due to its high adsorption selectivity towards Li + . Herein, a new type of Zr-doped Ti-LIS (HZrTO) was synthesized by a simple calcination method. The adsorption capacity increased from 56.3 mg g −1 (before doping) to 93.2 mg g −1 after doping in LiOH solution (lithium 1.8 g L −1 ). The adsorption isotherm and adsorption kinetics of HZrTO accord with the Langmuir isotherm and the pseudo-second-order kinetic equation, respectively. Batch experiments showed that HZrTO has good stability and selectivity. In addition, HZrTO was granulated via epoxy resin (E-12), and the obtained granular adsorbent showed good adsorption capacity, excellent stability and high selectivity towards Li + .
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Ya Su,Zhigang Xie,Min Zheng
Carbon dots (CDs) with concentration-modulated luminescence were obtained by pyrolysis of citric acid (CA) and thiourea (TU). CDs exhibit multi-colored emission by varying their concentrations. As a contrast, Zr-doped CDs (ZrCDs) were prepared from CA, TU and ZrCl 4 in a similar way. To our surprise, no concentration-dependent emission were observed in ZrCDs. Structural and optical characterizations prove that the concentration-tunable fluorescence is attributed to the aggregation between CDs. As the concentration increases, the aggregation of CDs results in a gradual decrease in the band gaps (from 2.18 eV to 1.56 eV), which ultimately causes the fluorescence to redshift continuously. However, ZrCDs are always in a highly dispersed state no matter how the concentration goes up, the zirconium complexes on the surface of ZrCDs prevents them from aggregation and maintains the band gap of ZrCDs at about 2.21 eV. Therefore, we proposed an aggregation-induced multicolor emission mechanism for CDs, which has a certain reference significance for exploiting the potential applications of CDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Xiaobo Bai,Chengyan Liu,Fucong Li,Zhongwei Zhang,Ying Peng,Ruifan Si,Baoquan Feng,Guojing Wu,Jie Gao,Haiqiao Wei,Lei Miao
Lead-free GeTe-based thermoelectric (TE) materials are most promising candidates to replace the environmentally harmful PbTe for TE application at middle temperature range, where high power factor ( PF ) is significantly important for high power generation if the cost of heat source is low enough. In this study, we report for the first time that the PF of GeTe can be greatly enhanced by tailoring the interaction between Te 5s 2 lone pair and antibonding orbitals, which is induced by the hybridization of Zr 4d 2 electrons with antibonding orbitals. As a result, the contribution of Ge 4s 2 electrons to the valence band is promoted, leading to the band sharpening at the valence band maximum in rhombohedral phase, and simultaneous band sharpening at the valence band maximum and band flattening at the conduction band minimum in cubic phase. Lower band effective mass m b * effectively increases the carrier mobility to a very high value of ∼121 cm −2 V −1 s −1 (300 K), and the Seebeck coefficient is improved by the reduced detrimental effect of minority carrier in cubic phase, enhancing the maximum PF up to a record value of ∼5503 μW m −1 K −1 . With the assistance of reduced thermal conductivity, a peak zT of ∼1.9 is achieved at 673 K, which is one of the highest values among single doped GeTe. This work provides a new guidance to enhance the TE performance of GeTe-based materials.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 4
·651
·
IF 3.9
Jiaqi Du,Yidan Peng,Xu Guo,Guoliang Zhang,Fengbao Zhang,Xiaobin Fan,Wenchao Peng,Yang Li
Researchers studying heterogeneous catalysis are intrigued by single-atom catalysts (SACs) due to their ultrahigh atomic utilization. However, only a few reports on SAC-catalyzed classical organic transformations are available. In this work, atomically dispersed Pd sites are confined to a ZrO2hybridized N-doped carbon skeleton with a smart design. UiO-66-NH2is used to anchor Pd atoms by the coordination of the donor atoms including lone pairs of electrons and metal atoms. Subsequently, the in situ introduction of ZrO2doping is achieved using pyrolysis, which helps improve the catalytic performance by modulating the electronic state. The Pd@ZrO2/N–C catalyst obtained from the unique design exhibits a high yield (99%) in eco-friendly media with an extremely low noble metal dosage (0.03 mol% Pd) for the Suzuki reaction. Moreover, Pd@ZrO2/N–C remains highly active after being reused several times and possesses versatility in a variety of substrates. This strategy offers a feasible alternative to designing SACs with atomically dispersed noble metals for heterogeneous reactions.Keywords:palladium;heterogeneous catalyst;Suzuki reaction;ZrO2doping;N-doped carbon
研究领域:
化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Muhammad Anas,Asad Ali,Abdul Ghaffar Khan,Aiyeshah Alhodaib,Abid Zaman,Tanveer Ahmad,Vineet Tirth,Ali Algahtani,Shohab Ahmad,Barno Sayfutdinovna Abdullaeva,Tawfiq Al-Mughanam,Muhammad Aslam
In this work, new compositions of Sr0.8Mg0.2(Sn1–xZrx)O3 0.00 ≤ x ≤ 0.06 ceramics are designed and synthesized by the conventional solid-state route. The influence of Zr doping on the phase, microstructural, optical, and dielectric properties is thoroughly investigated. The peaks (0 0 4) and (1 1 0) are observed to shift toward lower 2θ values, due to the variation of the ionic radius between Zr4+ and Sn4+. X-ray diffraction patterns reveal the orthorhombic structure with the space group Pbnm. Scanning electron microscopy images reveal the presence of pores and particles with a high degree of agglomeration. The functional groups and modes of vibration are determined by Fourier transform infrared spectroscopy of the prepared metal oxide samples. The existence of green emission of all the synthesized samples around 554.91 nm is identified by photoluminescence spectroscopy. The dielectric properties of the fabricated samples are measured by using an impedance analyzer. The values of the tangent loss and relative permittivity are found to decrease with increasing frequency.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Wenwen Lin,Siyu Yao,Hao Chen,Shenglai Li,Yang Xia,Yuan Yao,Jing Li,Dangguo Cheng,Jie Fu
Electrochemical nitrogen reduction reaction (NRR) to produce ammonia under ambient conditions is considered as a promising approach to tackle the energy-intensive Haber-Bosch process, but the low Faradaic efficiency and yield of NH 3 are still a challenge. Herein, a carbon-vacancies enriched mesoporous g-C 3 N 4 is developed by an in situ Zr doping strategy. The in situ mesoporous-forming mechanism is deeply understood by TPSR to reveal the functions of Zr dopant that pulls C from the precursor of C 3 N 4 , resulting the formation of homogeneous mesopores with about 57% of the one C-defective s-triazine ring in C 3 N 4 . Due to the defect sites obtained in metal doping synthesis, the RuAu bimetallic supported catalyst (RuAu 3 /0.3Zr-C 3 N 4 ) exhibits effective NRR performance with a Faraday efficiency of 11.54% and an NH 3 yield of 5.28 μg h −1 mg −1 cat. at −0.1 V (RHE), which is nearly 10 times higher than that of RuAu 3 /C 3 N 4 catalyst. This work proposes a simple and template–free preparation method for the high defect density mesoporous C 3 N 4 , and provides new possibilities of a wide application of mesopore g-C 3 N 4 .
研究领域:
材料科学
·
电催化
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2020
·
IF 2.029
Zijun Sun,Guisong Fang,Jinglin Li,Jiahuan Mo,Xiong He,Xu Wang,Zhiqiang Yu
Hematite (α-Fe 2 O 3 ) is one of the promising photoanode materials for photoelectrochemical (PEC) water splitting, but its poor bulk charge transfer has been challenging towards its practical application. Herein, we have synthesized the (Ti, Zr) co-doped hematite by a facile hydrothermal method. The cooperation of (Ti, Zr) co-doped hematite yields photocurrent density of 1.51 mA cm −2 at 1.23 V vs. RHE and IPCE of 17.3% at 400 nm. The structural and PEC analysis indicate that the considerably PEC performance improvement is contributed to the higher carrier density and enhanced charge transfer of the synergistic effect of Ti and Zr co-doping.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-12
·
IF 4.259
Song Jun,Wang Xueqin,Yan Jianhua,Yu Jianyong,Sun Gang,Ding Bin
Self-standing photocatalytic membranes constructed from TiO 2 nanofibers hold great promise in environmental remediation; however, challenges still remained for the poor mechanical properties of polycrystalline TiO 2 nanofibers. Herein, soft Zr-doped TiO 2 (TZ) nanofibrous membranes with robust mechanical properties and enhanced photocatalytic activity were fabricated via electrospinning technique. The Zr 4+ incorporation could effectively inhibit the grain growth and reduce the surface defects and breaking point of TiO 2 nanofiber. The as-prepared TZ membranes were composed of well-interconnected nanofibers with a high aspect ratios, small grain size and pore size, which exhibited good tensile strength (1.32 MPa) and showed no obvious damage after 200 cycles of bending to a radius of 2 mm. A plausible bending deformation mechanism of the soft TZ membranes was proposed from microscopic single nanofiber to macroscopical membranes. Moreover, the resultant TZ membranes displayed better photocatalytic performance for methylene blue degradation compared to a commercial catalyst (P25), including high degradation degree of 95.4% within 30 min, good reusability in 5 cycles, and easiness of recycling. The successful preparation of such fascinating materials may open up new avenues for the design and development of soft TiO 2 -based membranes for various application.
研究领域:
环境科学
·
材料科学
✓ 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）