INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·Vol. 44
·期 59
·31008-31019
·
IF 4.084
Jiayuan Hu,Yuhang Li,Shengsen Zhang,Qiao Zhang,Yunpeng Liu,Jianliang Zuo,Qiong Li,Feng Peng
The substitution of noble metal platinum catalyst is one of the important research contents for sustainable development and is also the key to the practical application of photoelectrochemical (PEC) hydrogen production . In this work, we loaded the 1T-2H mixed phase MoS 2 on the hydrogenated anatase/rutile heterophase TiO 2 (A-H-RTNA) by hydrothermal method to prepare a new MoS 2 /A-H-RTNA electrode material. The prepared material exhibited higher carrier density, lower PL intensity and higher conductivity than Pt/A-H-RTNA because 1T-MoS 2 has more active sites and lower charge transfer resistance than Pt. With the bias voltage of −0.4 V, the optimized 16MoS 2 /A-H-RTNA as photocathode shows the largest PEC hydrogen production rate of 1840 mmol m −2 h −1 , which is 2.9 and 2.2 times higher than those of A-H-RTNA (625 mmol m −2 h −1 ) and Pt/A-H-RTNA (848 mmol m −2 h −1 ), respectively. We innovatively used the prepared 16MoS 2 /A-H-RTNA film as counter electrode instead of Pt electrode to construct a PEC system without any noble-metal. The result demonstrates that the noble-metal-free MoS 2 loaded on TiO 2 electrode as counter electrode has 75% PEC activity of noble metal Pt electrode. This study develops a PEC method for hydrogen evolution , which no longer depends on precious metal platinum as cathode.
研究领域:
材料科学
·
光催化
·
氢能
·
电化学
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Shuqin Ren,Yaokun Fu,Lu Zhang,Lian Cong,Yichao Xie,Han Yu,Wenfeng Wang,Yuan Li,Lu Jian,Yu Wang,Shumin Han
Magnesium hydride (MgH 2 ) with high gravimetric hydrogen storage capacity is considered as one of the most potential hydrogen storage materials ; however, its development has been plagued by the high operating temperature and slow kinetics. In this study, we have design and synthesize a core-shell Ni/Fe 3 O 4 @MIL additive to aid the (de)hydrogenation of MgH 2 /Mg system via the co-catalytic effect of in-situ formed Mg 2 NiH 4 /Mg 2 Ni and Fe. The initial dehydrogenation temperature significantly reduces from 613 K to 517 K, and the MgH 2 -Ni/Fe 3 O 4 @MIL composite can reabsorb 4.17 wt% H 2 within 3600 s under 3.0 MPa H 2 at 373 K. Remarkably, the dehydrogenation activation energy of the composite decreases by 61.77 kJ/mol compared to the pure MgH 2 (159.71 kJ/mol). Moreover, the composite also shows good cycling stability without distinct capacity decay after cycling twenty times. Studies show that during dehydrogenation and hydrogenation processes, the Mg 2 NiH 4 /Mg 2 Ni act as catalysts to induce hydrogen desorption/absorption of MgH 2 /Mg. Meanwhile, the unique core-shell structure of the Ni/Fe 3 O 4 @MIL not only provides reaction sites, but also prevents the agglomeration of nanoparticles and maintains stable catalytic activity. This study provides a new idea for designing stable transition metal heterogeneous catalytic system to improve hydrogen storage performance of MgH 2 .
研究领域:
材料科学
·
氢能
·
纳米技术
·
催化
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·Vol. 48
·期 83
·32459-32468
·
IF 7.2
Chengguo Yan,Qinan Wu,Jiaguang Zheng,Dan Li,Jiahuan He,Yugang Shu,Meijia Liu,Liuting Zhang
NaBH 4 has been considered as one of the ideal hydrogen carriers with comparatively high hydrogen capacities towards traditional hydrogen storage materials . However, the hydrogen generation from NaBH 4 needs excess water and costly catalysts to achieve a complete and fast hydrogen release. Herein, we report an innovative strategy to use solid-state multi-hydroxyl mannitol as a reactant towards NaBH 4 , which brings fast and controllable hydrogen release below 80 °C. More than 4.1 wt% H 2 (83% of the theoretical capacity) could be released totally from the NaBH 4 -mannitol composite with high purity. Structural and morphological studies further reveal that mannitol acts as a bi-functional additive to react with NaBH 4 during hydrogen release and protect NaBH 4 from moisture during storage. This work shows potential in developing all-solid-state hydrogen production systems with high-capacity borohydrides .
研究领域:
材料科学
·
氢能
·
化学工程
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2016
·
IF 2.435
Yongji Xin,Yan Lu,Changcun Han,Lei Ge,Ping Qiu,Yujing Li,Siman Fang
In this paper, ultrathin 2D TiO 2 nanosheets which modified with ultrafine dispersions of NiS cocatalyst were successfully prepared via a low-cost and in-situ synthesis approach. The physical and chemical properties of the as-obtained NiS/TiO 2 nanosheets samples were investigated by a variety of analytical techniques. Cooperated with the photocatalytic hydrogen evolution tests and surface photovoltage spectroscopy (SPV) experiments, it can be deduced that the NiS is an efficient cocatalyst, which significantly limited the recombination of photogenerated electron-hole pairs in ultrathin 2D TiO 2 nanosheets and consequently improve the hydrogen evolution activity. The influence of different molar ratios of NiS on the photocatalytic activity was explored and the 5 mol% NiS/TiO 2 composite photocatalyst showed the highest photoactivity which the corresponding H 2 -production rate was 313.6 μmol h −1 g −1 under the UV–vis light irradiation. The optimal H 2 evolution rate is 36 times as much as the value of pure TiO 2 nanosheets. The photocatalytic mechanism of NiS cocatalysts on the enhanced performance of the photocatalytic activity of TiO 2 nanosheets is proposed and confirmed by SPV results.
研究领域:
材料科学
·
光催化
·
纳米材料
·
氢能
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Na Yang,Fanqi Bu,Mengyue Gu,Yonghong Cheng,Jinying Zhang
The hydrolysis of LiAlH4 is a feasible path to supply hydrogen at subzero temperatures due to its high hydrolysis reactivity and hydrogen purity. However, the extremely fast hydrolysis reaction of LiAlH4 hindered its practical application due to its kinetic instability and safety risks caused by the exothermic effect of the reaction. Herein, hydrophobic graphene nanosheets (GNS) have been coated on the surfaces of LiAlH4 particles (LiAlH4@GNS composites) to slow the hydrolysis kinetics of LiAlH4, especially at subzero temperatures. The GNS coating processes have been found to introduce not only GNS coating but also fragmentation of LiAlH4 particles. The coating process was found to hinder the hydrolysis reaction of LiAlH4 with increasing GNS coating to 3.82 wt %, while the hydrolysis of LiAlH4 was found to increase with further GNS coating process due to significant fragmentation effects. The hydrolysis speeds of LiAlH4@GNS (D50 = 100 μm, Dδ = 1.30) with GNS coating (∼3.82 wt %) have been demonstrated to be reduced to 70% of that of pristine LiAlH4, where the conversion rates were found to be still higher than 99.0% at −40 to 0 °C. The GNS coating is considered to serve as a barrier to hinder the free diffusion of H2O molecules toward the reaction interface at the initial stage of the reaction, resulting in longer induction periods of the composites than those of pristine LiAlH4. The hydrolysis of LiAlH4@GNS has been demonstrated to follow the shrinking core model controlled by liquid film diffusion, where the GNS coating plays an important role in extending the diffusion distance and reducing the diffusion efficiency of substances within the liquid film layer.
研究领域:
材料科学
·
氢能
·
纳米材料
·
化学动力学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Dandan Peng,Ying Zhang,Shumin Han
Magnesium hydride is considered as a promising candidate for hydrogen storage; however, the sluggish kinetics and thermodynamic stability seriously obstruct its industrial applications. Hence, in order to improve the hydrogen storage performances of magnesium hydride, NiS@C additive was ball-milled with Mg powder to build NiS@C/Mg. The MgH2/Mg2NiH4 polyphase hydrides were in situ formed after hydrogenated activation and turned into Mg/Mg2Ni phases during the dehydrogenation process, establishing a cycle of hydrogen absorption and desorption. The NiS@C/Mg composite showed enhanced de/hydrogenation rates: it could quickly absorb 6.02 wt % H2 within 5 min at 250 °C and desorb 5.34 wt % H2 at 300 °C. Moreover, even at the temperature of 50 °C, it could reach 3.23 wt % hydrogen absorption capacity, and the apparent hydrogen desorption activation energy for MgH2 decreased to 60.45 kJ mol–1. It also delivered a high cyclic stability performance of 98.9% for hydrogen absorption and 98.5% for hydrogen desorption after 50 cycles. The enhanced de/absorption kinetics of NiS@C/Mg were ascribed to the synergistic effects of multiple-phase MgH2/Mg2NiH4 hydrides and the in situ formed MgS catalyst, and the existence of C also effectively prevented the passivation and agglomeration of multiple-phase particles. The method of in situ generating of multiple-phase hydrides and catalysts provides a new view for the preparation of high-performance hydrogen storage materials.
研究领域:
材料科学
·
氢能
·
纳米复合材料
·
能量存储
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 43
·13510-13523
·
IF 0
Lina Chong,Jianxin Zou,Xiaoqin Zeng,Wenjiang Ding
In the present study, a new hydrogen storage system, being able to reversibly absorb/desorb hydrogen at fairly low temperatures, was developed based on a 3NaBH4–PrF3 composite. It is shown that 3 wt% of reversible hydrogen sorption can be achieved in the 3NaBH4–PrF3 composite at 400 °C with fast kinetics. After the addition of 5 mol% VF3, the dehydrogenation kinetics of the 3NaBH4–PrF3 composite can be significantly improved. The onset dehydriding temperature is lowered down to 46 °C in vacuum, and the dehydrogenation finishes in 2 min at 400 °C. Both the dehydrogenation enthalpy and activation energy of 3NaBH4–PrF3 can be lowered down through the addition of VF3. In particular, the dehydrogenation products of the 3NaBH4–PrF3–5 mol% VF3 composite can be rehydrogenated at a temperature as low as 48 °C with the regeneration of NaBH4. At 84 °C, a reversible hydrogen sorption of about 1.2 wt% can be achieved in the 3NaBH4–PrF3–5 mol% VF3 composite. The improvement in hydrogen sorption properties can be mainly attributed to the formation of the VB2 phase during dehydrogenation as an efficient catalyst, which maintains well its catalytic effect in the re-/dehydrogenation cycles. Based on a series of controlled experiments and phase analyses, the de-/rehydrogenation mechanisms of the 3NaBH4–PrF3 composite without and with VF3 addition are proposed and discussed in detail.
研究领域:
材料科学
·
氢能
·
固态化学
✓ 已验证
DOI
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Yiwen Zhang,Xuezhang Xiao,Bosang Luo,Xu Huang,Meijia Liu,Lixin Chen
A significant improvement in reversible de/rehydrogenation properties of MgH2 doped with 2.5 wt % LiAlH4 and 2.5 wt % LiBH4 additives is achieved by reactive ball milling. Careful comparison studies show that a small amount (total mass ratio of ≤5 wt %) of LiBH4 and/or LiAlH4 can improve the hydrogen desorption performance of MgH2 in terms of reducing hydrogen desorption temperature, enhancing hydrogen desorption kinetics, and increasing hydrogen capacity. In particular, the MgH2 co-doped with LiAlH4–LiBH4 exhibits the best dehydrogenation properties, which starts to release hydrogen at about 280 °C and releases a high hydrogen capacity of 7.62 wt % with superior reaction kinetics. The activation energy of hydrogen desorption is decreased from 187.8 kJ/mol (ball-milled MgH2) to 155.8 kJ/mol. It can also uptake 7.7 wt % H2 within 15 min at 300 °C with a stable hydrogen absorption kinetics in the first 10 cycles. This synergistic effect of LiBH4 and LiAlH4 additives on improved hydrogen absorption/desorption properties is attributed to the in situ formation of Li3Mg7, Mg17Al12, and MgAlB4 new phases acting as the “catalytic active sites” to facilitate the diffusion of hydrogen through the reaction barriers in the de/hydrogenation cycles of MgH2. Moreover, these new phases can be rehydrogenated into MgH2, LiBH4, and Li3AlH6 hydrides, which further enhance the hydrogen capacity of co-doped sample more than the theoretical capacity of primitive MgH2.
研究领域:
材料科学
·
氢能
·
固态化学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Yongyang Zhu,Qing Zhou,Liming Zeng,Daifeng Wu,Renheng Tang,Shun Wang
The lack of efficient and economic synthesis techniques for LiBH4 limits its popularization as a high-capacity hydrolysis material to supply hydrogen for fuel cells. Reversibly converting the low-cost hydrolytic products, typically hydrated lithium borate (LiBO2·xH2O), into LiBH4 via Mg reductants appears attractive, bringing the hope to realize a closed loop for LiBH4 hydrolysis and regeneration; however, the strong B–O bonds in LiBO2·xH2O and the weak reducing capacity pose a severe kinetics obstacle with low yield. Herein, we propose an optimized method to produce LiBH4 by facile ball milling under ambient conditions, with Li2B4O7·3H2O and LiOH·H2O as reactants, Mg-RE that was obtained by introducing cheap rare-earth metals (RE) to normal Mg as reductants, and minor MgH2 as reaction triggers and supplementary hydrogen sources. The usage of Mg-RE can not only improve the contacting efficiency between reactants due to its grind-aiding induced by hard and brittle features but also empower the reducing ability, since the H-philic nature of RE makes Mg-RE prone to hydrogenation, in situ forming highly active intermediate phases that accelerate the conversion of initial H+ to H–. A high LiBH4 yield of 33% can thus be achieved in a relatively short ball milling time of 10 h. This work enriches the synthesis pathways of LiBH4 and boosts its competitiveness for scaled applications.
研究领域:
材料科学
·
氢能
·
固态化学
·
机械化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2012
·Vol. 42
·期 10
·3402-3409
·
IF 3.838
Bo Chai,Tianyou Peng,Xiaohu Zhang,Jing Mao,Kan Li,Xungao Zhang
A novel nanostructured carbon/TiO2 nanocomposite photocatalyst is firstly fabricated via a facile hydrothermal process by using fullerene (C60) decorated single-walled carbon nanotubes (SWCNTs) as carbon source, which is denoted as C60-d-CNTs. The obtained nanostructured carbon/TiO2 nanocomposites are characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectra (DRS), Raman spectra, X-ray photoelectron spectroscopy (XPS) and photoluminescence spectra (PL), and then are used as catalysts for photocatalytic hydrogen production. It is found that the kinds and contents of various carbon nanostructured materials (such as SWCNTs, C60 and C60-d-CNTs) coupled with TiO2 can significantly enhance the photoactivity for hydrogen production, and the 5 wt% C60-d-CNTs/TiO2 nanocomposite exhibits the best performance. Experimental results suggest that the C60-d-CNTs as a novel carbon nanostructured material could be more beneficial for the photogenerated carrier separation than SWCNTs and C60 when these carbon nanostructured materials are coupled with TiO2.
研究领域:
材料科学
·
纳米技术
·
光催化
·
氢能
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·Vol. 48
·期 47
·17957-17969
·
IF 7.2
Wei Zhang,Dongliang Zhao,Jun Li,Zeming Yuan,Shihai Guo,Yan Qi,Yanghuan Zhang
Ball milling the powders of Mg-based alloys with transition metal compounds is effective for improving their hydrogen storage performances. In this experiment, the alloys of La 1.7 Y 0.3 Mg 16 Ni + x wt.% TiF 3 ( x = 0–10) were prepared through mechanical milling technology. XRD , SEM , HRTEM and granulometry were used to measure the composition and microstructure of alloys. The isothermal hydrogen storage property was measured by a Sievert apparatus. The results reveal that the TiF 3 additive in ball-milled samples transforms into MgF 2 and TiH 2 after the first hydrogen absorption . Adding TiF 3 enhances the crystallinity and reduces the average particle and crystallite sizes of alloys, which is beneficial to accelerating hydriding and dehydriding kinetics. Adding 7 wt% TiF 3 into alloy decreases the dehydrogenation activation energy from 72.2 to 64.0 kJ/mol and improves the hydrogen absorption rate at low temperatures, absorbing 3.50 wt% H in 0.5 min at 323 K.
研究领域:
材料科学
·
氢能
·
金属合金
·
机械球磨
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·Vol. 42
·期 17
·12210-12219
·
IF 3.582
Tianjun Chen,Chengjie Song,Mingshan Fan,Yuanzhi Hong,Bo Hu,Longbao Yu,Weidong Shi
In this work, novel CuS/g-C 3 N 4 composite photocatalysts were successfully prepared via a simple in-situ growth method. CuS nanoparticles , with an average diameter of ca.10 nm, were well dispersed on the surface of g-C 3 N 4 , revealing that g-C 3 N 4 nanosheets were promising support for in-situ growth of nanosize materials. The CuS/g-C 3 N 4 composites exhibited highly enhanced visible light photocatalytic H 2 evolution from water-splitting compared to pure g-C 3 N 4 . The optimum photocatalytic activity of 2 wt% CuS/g-C 3 N 4 composite photocatalytic H 2 evolution was about 13.76 times higher than pure g-C 3 N 4 . The enhanced photocatalytic activity is attributed to the interfacial charge transfer (IFCT). In this system, electrons in the valence band (VB) of g-C 3 N 4 can transfer directly to CuS clusters, causing the reduction of partial CuS to Cu 2 S, which can act as an electron sink and co-catalyst to promote the separation and transfer of photo-generated electrons. The accumulated photoinduced electrons in CuS/Cu 2 S clusters could effectively reduce H + to produce H 2 . This work provides a possibility for constructing low-cost CuS as a substitute for noble metals in the photocatalytic production of H 2 via a facile method based on g-C 3 N 4 .
研究领域:
材料科学
·
光催化
·
氢能
·
纳米复合材料
·
可再生能源
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）