ANALYTICA CHIMICA ACTA
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2025
·
IF 6
Peng Han,Yuan Li,Bin Zhao,Huiliang Li,Zheng Wang,Xue Liu,Weihua Meng
Background Photonic actuator materials that change their color in response to stimuli are uniquely suited for analyte sensing and visual detection. However, the changing iridescence produced by conventional photonic crystal structures in hydrogel materials can seriously confuse optical readouts, thus limiting their widespread application. Results Here, we report novel visual urea sensors with angle-independent structural colors. The urease-modified hydrogels were constructed into amorphous photonic structures. Based on the urease catalytic action induced charge variation within the hydrogel matrix, it leads to the volume change and corresponding diffraction wavelength shift of the photonic hydrogel biosensors, thereby enabling the stable and repeatable detection of urea. The response range of the sensors to urea solution ranged from 0 to 80 mM, with a linear range of 1–10 mM and a detection limit of 0.36 mM. Significance The visual and label-free sensors with non-iridescent structural colors have great potential in various response fields that require stable colors and open up a new avenue for the development of biomedical sensing photonic devices.
研究领域:
生物医学传感
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材料科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Lingxuan Meng,Lingye Zhang,Suyi Liu,Feng Wang,Huimin Wu
Pollution-free and low-cost bifunctional catalysts are important part for hydrogen production . In this paper, composite catalysts Ni 0.2 Mo 0.8 N/CeO 2 -x/NF (x = n(Ce)/n(Ni)- 0.1, 0.3, 0.5) were synthesized via hydrothermal and calcination methods on foam nickel (NF). Experimental results show that the composites have better properties than CeO 2 /NF, Ni 0.2 Mo 0.8 N/NF and MoN/CeO 2 /NF. The electrochemical properties of the composites depend on the ratio of nickel and cerium . A proper proportion of nickel leads to a larger specific surface area, increased electron capacity, more active sites, and better overall performance. Among the tested composites, Ni 0.2 Mo 0.8 N/CeO 2 -0.3/NF exhibits the best electrochemical performance and is well-suited for catalyzing the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR). For HER, the potential is −120 mV @ 100 mA cm −2 . And for UOR, the UOR potential is only 1.462 V @ 100 mA cm −2 . A two-electrode electrolyzer of Ni 0.2 Mo 0.8 N/CeO 2 -0.3/NF|| Ni 0.2 Mo 0.8 N/CeO 2 -0.3/NF was also built. Overall urea splitting (OUS) is 1.672 V @ 100 mA cm −2 , which is 187 mV smaller than overall water splitting (OWS, 1.859 V). Therefore, Ni 0.2 Mo 0.8 N/CeO 2 has potential application in hydrogen production from urea-rich wastewater electrolysis.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
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IF 6.371
Yihui Wu,Zesheng Sun,Yuxin Wang,Li Yin,Zhen He,Zejie Zhang,Muhammad D. Hayat,Qianhao Zang,Jiqiong Lian
The development of efficient and low-cost bifunctional electrocatalysts for hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) is highly challenging in urea-water-alkali electrolyzers. Herein, nickel-selenium electrocatalysts (denoted as Ni-Se) were controllably grown on Ni foam by a facile and simple cyclic voltammetric electrodeposition for overall urea electrolysis. Considering the good conductivity and high hydrophilic surface of Ni-Se@NF, the optimized Ni-Se electrocatalyst exhibited the eminent HER and UOR catalytic competence. In 1 M KOH with 0.33 M urea electrolyte, Ni-Se electrocatalysts required an overpotential of 181 mV for HER and potential of 1.347 V versus reversible hydrogen electrode for UOR to achieve a current density of 10 mA·cm −2 . Additionally, the electrocatalyst showed good durability in both HER and UOR. Moreover, the electrolyzer assembled by Ni-Se electrocatalysts as electrode couple exhibited a remarkable activity with a small cell voltage of 1.41 V to reach 10 mA·cm −2 for overall urea-water electrolysis.
研究领域:
材料科学
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电化学
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能源转换与存储
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产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 4
·727
·
IF 3.9
Jie Ren,Pingping Yang,Liuliu Wang,Hongyu Chen,Xingyu Lu,Qing Yang,Li Zou,Cheng Huang,Jiale Xie
Photoelectrochemical (PEC) urea splitting is of great significance for urea wastewater remediation and hydrogen production with low energy consumption simultaneously. Nickel hydroxides as electrocatalysts have been widely investigated for urea electrolysis. However, it is an open question how to synthesize highly catalytic Ni(OH)2for the PEC urea splitting. Herein, we take advantage of the instability of metal–organic frameworks (MOFs) to perform an in situ synthesis of Ni(OH)2catalysts on the surface of TiO2nanorod arrays. This transformed Ni(OH)2(T-Ni(OH)2) possesses a superior PEC catalytic activity for water/urea splitting in comparison to the Ni(OH)2prepared by the impregnation method. The in situ transition of a Ni-MOF is accomplished through an electrochemical treatment under AM1.5G illumination in a KOH-and-urea mixed electrolyte. The specific transition mechanism of Ni-MOFs is the substitution of ligands with OH−in a 1 M KOH electrolyte and the successive phase transition. The T-Ni(OH)2@TiO2photoanode delivers a high photocurrent density of 1.22 mA cm−2at 1.23 VRHE, which is 4.7 times that of Ni(OH)2@TiO2prepared with the impregnation method. The onset potential of T-Ni(OH)2@TiO2is negatively shifted by 118 mV in comparison to TiO2. Moreover, the decline of photocurrent during the continuous test can be recovered after the electrochemical and light treatments.Keywords:photoelectrochemical urea splitting;urea oxidation reaction;titanium dioxide;metal–organic framework;in situ transition
研究领域:
材料科学
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电化学
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环境科学
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产品关联
DOI
高影响因子
CELLULOSE
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2017
·Vol. 25
·期 1
·233-243
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IF 3.417
Lv Miaomiao,Ma Xiaofei,Anderson Debbie P.,Chang Peter R.
Cellulose spheres were selected as an economical and biodegradable carrier for urease immobilization. The high crystallinity cellulose spheres (Ces) were crosslinked using citric acid and then oxidized using sodium periodate to produce aldehyde groups on the Ces surface that would bind covalently with the amino groups of urease through a Schiff base reaction. Ces, the obtained dialdehyde cellulose spheres (DACes) and cellulose spheres immobilized by urease (UrCes) were characterized by FTIR, XRD, SEM and TG. The results demonstrated the successful modification of Ces and immobilization of urease, along with the retention of the original spherical morphology and improved thermal stability. As an adsorbent, UrCes had both a greater adsorption capacity for urea and a greater specific selective adsorption than DACes. Urease was respectively immobilized on DACes with 19, 31 and 45% aldehyde contents to obtain UrCes1, UrCes2 and UrCes3. The maximum removal capacities of UrCes1, UrCes2, and UrCes3 for urea were 243.3, 276.2, and 187.6 mg g −1 , while only 10.71, 15.08 and 20.50 mg g −1 l -phenylalanine were adsorbed, respectively.
研究领域:
生物化学
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环境科学
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产品关联
DOI
高影响因子
Microorganisms
·
2024
·Vol. 12
·期 4
·685
·
IF 4.1
Yiming Jiang,Yueyue Zhu,Weitie Lin,Jianfei Luo
The application of urea in agricultural soil significantly boosts nitrous oxide (N2O) emissions. However, the reason for nitrite accumulation, the period of nitrite-oxidizing bacteria (NOB) suppression, and the main NOB species for nitrite removal behind urea fertilization have not been thoroughly investigated. In this study, four laboratory microcosm experiments were conducted to simulate urea fertilization in agricultural soils. We found that within 36 h of urea application, nitrite oxidation lagged behind ammonia oxidation, leading to nitrite accumulation and increased N2O emissions. However, after 36 h, NOB activity recovered and then removed nitrite, leading to reduced N2O emissions. Urea use resulted in an N2O emission rate tenfold higher than ammonium. During incubation,Nitrobacter-affiliated NOB growth decreased initially but increased later with urea use, whileNitrospira-affiliated NOB appeared unaffected. Chlorate suppression of NOB lasted longer, increasing N2O emissions. Urease inhibitors effectively reduced N2O emissions by slowing urea hydrolysis and limiting free ammonia production, preventing short-term NOB suppression. In summary, short-term NOB suppression during urea hydrolysis played a crucial role in increasing N2O emissions from agricultural soils. These findings revealed the reasons behind the surge in N2O emissions caused by extensive urea application and provided guidance for reducing N2O emissions in agricultural production processes.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
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2023
·
IF 5.6
Liangliang Cheng,Wanlu Zheng,Ya-Nan Zhang,Xuegang Li,Yong Zhao
A highly sensitive fiber-optic urea sensor was designed and experimentally demonstrated based on surface plasmon resonance (SPR) effect and metal-organic zeolite framework (MOF), [zeolite imidazole skeleton-8 (ZIF-8)]/urease modification. The SPR effect was excited by plating gold film on the thin core fiber (TCF) in multimode-thin core-multimode fiber (MMF) structure, which behaved high refractive index sensitivity. The ZIF-8/urease composite film was grown on the gold film by rapid aqueous phase synthesis method, in which the ZIF-8 could immobilize more urease and made urease and urea fully contact. Since the urease catalyzed urea hydrolysis would change the refractive index, the measurement of urea concentration was realized with high sensitivity and good selectivity. Experimental results showed that the urea measurement sensitivity of the proposed sensor could reach 6 nm/mM within the concentration range of 1–7 mM, which has great application potential in the field of human health monitoring.
研究领域:
光学传感
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生物医学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2013
·
IF 0
Lei Wang,Sha Wang,Xiangyun Deng,Yucang Zhang,Chunrong Xiong
Coconut shell activated carbon (AC)-tethered urease (from jack bean) was successfully developed to degrade urea in a packed bed reactor. The loading capacity of urease in AC was 78.8 mg/g. The tethered enzyme showed a maximum activity at 70 °C and pH 7.2. For higher than 75% of the maximum activity, the tethered urease showed a broader temperature range of 42–80 °C compared to 45–75 °C for the free enzyme. Similarly, the tethered urease had an increased stability against the changes of pH. The Km value of the free urease was 0.271 mol/L and 0.345 mol/L for the tethered one. This may be caused by the conformational changes of the enzyme. The Vmax values were 0.215 and 0.110 mol/min for the tethered and free ureases, respectively, which is reflected by an increase in catalytic activity. The catalytic degradation of urea was performed in a packed bed reactor. The remaining activity of the tethered urease was over 80% after 50 h of operation.
研究领域:
生物化学
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环境科学
✓ 已验证
DOI
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2020
·
IF 4.939
Xinzhu Wen
It is crucial for the storage and conversion of hydrogen energy to substitute the low theoretical potential of urea oxidation reaction (UOR) for the high theoretical potential of anodic water electrolysis (oxygen evolution reaction (OER)). In this paper, it puts forward a brief and scalable strategy, so as to synthesize a novel bifunctional nickel-iron layered double hydroxide and multi-walled carbon nanotube composites supported on Ni foam, represented as NiFe-LDH/MWCNTs/NF. Electrochemical measurements demonstrate that NiFe-LDH/MWCNTs/NF is able to realize an efficient electrocatalysis for UOR. During this process, merely a potential of 1.335 V is needed at 10 mA cm −2 , which can be taken to replace OER, thus reducing overpotential in H 2 -production as well as power consumption . In addition, NiFe-LDH/MWCNTs/NF also exhibits electro-defense electrocatalytic efficiency to achieve the reaction of hydrogen evolving process, which provides a low overpotential of 98 mV at 10 mA cm −2 . To further prove it, all-water-urea electrolysis measurement is carried out in 1 M KOH and 0.5 M Urea with NiFe-LDH/MWCNTs/NF as cathode and anode respectively. NiFe-LDH/MWCNTs/NF||NiFe-LDH/MWCNTs/NF electrode manages to provide 10 mA cm −2 at a voltage of merely 1.507 V, 156 mV lower than that of water splitting, which proves its commercial viability in energy-saving hydrogen production .
研究领域:
能源材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2023
·
IF 11.4
Zepeng Liu,Yueyao Hu,Jie Zhang,Ying Guan,Liping Zhang,Ping Ye,Tongtong Zhang,Xingyu Huang,Meng Wang,Hui Gao
Adsorbents with excellent physicochemical properties and green synthetic routes are desired for efficient removal of Congo red (CR) wastewater. Hence, a novel approach was proposed within this work. Biochar NCBC obtained from Medulla Tetrapanacis was synthesized through co-modification with urea/calcium chloride. NCBC exhibited an enormous surface area (750.09 m 2 /g) and a micro-mesoporous composite structure. Higher nitrogen content was detected on the surface of NCBC (8.17%) compared to that of urea directly modified biochar (4.63%). Nitrogen observed on the surface of NCBC was presented as graphitic N, pyrrolic N, amine N as well as pyridinic N. Kinetic and isothermal investigations revealed the active sites on NCBC to be homogeneous and bind to CR mainly by chemisorption. Calculated maximum sorption of CR on NCBC was 2512.82 mg/g basing on Langmuir model. Moreover, the practicality of NCBC was further proved by the cultivation of Nelumbo nucifera Gaertn. and Penicillium .
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2017
·Vol. 9
·期 11
·592
·
IF 3.364
Ping Liu,Xiao-Tong Chen,Hai-Mu Ye
In this study, polylactide/urea complexes were successfully prepared by the electrospinning method, then the host urea component was removed to obtain a coalesced poly(l-lactide) (PLLA)/poly(d-lactide) (PDLA) blend. The crystallization behavior of the coalesced PLLA/PDLA blend (c-PLLA/PDLA) was studied by a differential scanning calorimeter (DSC) and Fourier transform infrared (FTIR) spectroscopy. Thec-PLLA/PDLA was found to show better crystallization ability than normal PLLA/PDLA blend (r-PLLA/PDLA). More interestingly, thec-PLLA/PDLA effectively and solely crystallized into stereocomplex crystals during the non-isothermal melt-crystallization process, and the reason was attributed to the equally-distributing state of PLLA and PDLA chains in the PLLA/PDLA/urea complex, which led to good interconnection between PLLA and PDLA chains when the urea frameworks were instantly removed.Keywords:polylactide;urea;inclusion complex;crystallization;stereocomplex
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2021
·Vol. 102
·期 9
·3636-3643
·
IF 3.639
Jianyuan Jing,Shuiqin Zhang,Liang Yuan,Yanting Li,Yingqiang Zhang,Yanchen Wen,Bingqiang Zhao
BACKGROUND Humic acid (HA)-enhanced urea (HAU) is the top-selling efficiency-enhanced urea in China. Comprehensive investigation into the structure and efficacy of HA complex formation with urea (HACU) – the main reaction product during HAU's production – is required to clarify the reaction mechanism between HA and urea, and to provide guidance for the development of high-efficiency HAU. RESULTS HACU showed discrepant structural and compositional features from raw HA. Nitrogen (N) content in HACU was 7.3 times greater than that of HA. Several high-resolution analytical methods showed a sharp increase of ammonia in the gaseous product during HACU pyrolysis, suggesting that urea contributed N to HACU. HACU was characterized with significantly fewer carboxyl groups than in raw HA, implying that the carboxyl group was the main group in HA to participate in the reaction between HA and urea. The presence of amide-N in HACU verified the structure of the reaction product. Furthermore, both HACU and HA could enhance the biomass in hydroponically grown maize seedlings, but the highest stimulation for HACU came about when its carbon concentrations were 50–100 mg L −1 , higher than the optimal carbon concentration for HA (25 mg L −1 ), attributed to the lower carboxyl group content for HACU to some extent. CONCLUSION During HAU's production, reaction with N derived from urea to form amide-N decreased the carboxyl groups in HA, leading to higher concentrations for HACU required to achieve the similar bioefficacy of HA. © 2021 Society of Chemical Industry.
研究领域:
农业科学
·
植物生理学
✓ 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）