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1.
Hefeng Zhang Zhou Yang Wei Yu Hong Wang Weiguang Ma Xu Zong Can Li 《Liver Transplantation》2018,8(22)
Organolead halide perovskite materials have demonstrated great potential in the solar cells field owing to their excellent optoelectronic properties. However, the instability issue of the perovskites impedes the translation of their attractive features for the solar fuel production such as photoelectrochemical H2 production from water splitting. Herein, CH3NH3PbI3 a photocathode with a sandwich‐like structure is fabricated with a general and scalable approach toward addressing this issue. The photocathode exhibits an onset potential at 0.95 V versus reversible hydrogen electrode (RHE) and a photocurrent density of ?18 mA cm?2 at 0 V versus RHE with an impressive ideal ratiometric power‐saved efficiency of 7.63%. More impressively, the photocathode retains good stability under 12 h continuous illumination in water at wide pH range. This performance is much superior to that of the best perovskite‐based photoelectrode ever reported. 相似文献
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Siva Krishna Karuturi Heping Shen Astha Sharma Fiona J. Beck Purushothaman Varadhan The Duong Parvathala Reddy Narangari Doudou Zhang Yimao Wan Jr‐Hau He Hark Hoe Tan Chennupati Jagadish Kylie Catchpole 《Liver Transplantation》2020,10(28)
Realizing solar‐to‐hydrogen (STH) efficiencies close to 20% using low‐cost semiconductors remains a major step toward accomplishing the practical viability of photoelectrochemical (PEC) hydrogen generation technologies. Dual‐absorber tandem cells combining inexpensive semiconductors are a promising strategy to achieve high STH efficiencies at a reasonable cost. Here, a perovskite photovoltaic biased silicon (Si) photoelectrode is demonstrated for highly efficient stand‐alone solar water splitting. A p+nn+ ‐Si/Ti/Pt photocathode is shown to present a remarkable photon‐to‐current efficiency of 14.1% under biased condition and stability over three days under continuous illumination. Upon pairing with a semitransparent mixed perovskite solar cell of an appropriate bandgap with state‐of‐the‐art performance, an unprecedented 17.6% STH efficiency is achieved for self‐driven solar water splitting. Modeling and analysis of the dual‐absorber PEC system reveal that further work into replacing the noble‐metal catalyst materials with earth‐abundant elements and improvement of perovskite fill factor will pave the way for the realization of a low‐cost high‐efficiency PEC system. 相似文献
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Xiaoqiang An Tong Li Bo Wen Junwang Tang Ziyu Hu Li‐Min Liu Jiuhui Qu C. P. Huang Huijuan Liu 《Liver Transplantation》2016,6(8)
Understanding the interfacial electronic structures of heterojunctions, a challenging undertaking, is extremely important to the design of photoelectrodes for efficient water splitting. The heterostructured interfaces in terms of crystal defects at the atomic‐level exemplified by TiO2/BiVO4 are studied. Results from both experimental observations and theoretical calculations clearly confirm the spontaneous formation of defective interfaces in the heterostructures. TiO2/BiVO4 junction with engineered interfacial defects can efficiently increase the carrier density and extend the lifetime of electrons. The inherent phenomenon of defective electronic structures in different heterostructures creates a significant impact on their photoelectrochemical performance. The synergetic effect between defect‐mediated mechanism and organic quantum dots sensitization yields significantly increased photoconversion efficiency, which is even superior to that of common metal sulfide sensitized ones. This result demonstrates an approach worthy for the design and fabrication of defect‐mediated heterostructures for water splitting, without utilizing harmful metal sulfides. Moreover, new insights into the influence of intrinsic defects on the interfacial charge transfer process between two different semiconductors for energy‐related applications have also been provided. 相似文献
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Paula Dias Marcel Schreier S. David Tilley Jingshan Luo João Azevedo Luísa Andrade Dongqin Bi Anders Hagfeldt Adélio Mendes Michael Grätzel Matthew T. Mayer 《Liver Transplantation》2015,5(24)
Photoelectrochemical water splitting represents an attractive method of capturing and storing the immense energy of sunlight in the form of hydrogen, a clean chemical fuel. Given the large energetic demand of water electrolysis, and the defined spectrum of photons available from incident sunlight, a two absorber tandem device is required to achieve high efficiencies. The two absorbers should be of different and complementary bandgaps, connected in series to achieve the necessary voltage, and arranged in an optical stack configuration to maximize the utilization of sunlight. This latter requirement demands a top device that is responsive to high‐energy photons but also transparent to lower‐energy photons, which pass through to illuminate the bottom absorber. Here, cuprous oxide (Cu2O) is employed as a top absorber component, and the factors influencing the balance between transparency and efficiency toward operation in a tandem configuration are studied. Photocathodes based on Cu2O electrodeposited onto conducting glass substrates treated with thin, discontinuous layers of gold achieve reasonable sub‐bandgap transmittance while retaining performances comparable to their opaque counterparts. This new high‐performance transparent photocathode is demonstrated in tandem with a hybrid perovskite photovoltaic cell, resulting in a full device capable of standalone sunlight‐driven water splitting. 相似文献
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Junghyun Noh Hong Li Osman I. Osman Saadullah G. Aziz Paul Winget Jean‐Luc Brédas 《Liver Transplantation》2018,8(21)
Hematite (α‐Fe2O3) is widely used as a catalytic electrode material in photo‐electrochemical water oxidation, where its surface compositions and stabilities can strongly impact the redox reaction process. Here, its surface configurations in environmental or electrochemical conditions are assessed via density functional theory (DFT) calculations conducted at the Perdew, Burke, and Ernzerhof (PBE)+U level. The most energetically favorable surface domains of α‐Fe2O3 (0001) and (102) are predicted by constructing the surface phase diagrams in the framework of first‐principle thermodynamics. The relative surface stabilities are investigated as a function of partial pressures of oxygen and water, temperature, solution pH, and electrode potential not only for perfect bulk terminations but also for defect‐containing surfaces having various degrees of hydroxylation and hydration. In order to assess the impact on the redox reactions of the surface planes as well as of the extent of surface hydration/hydroxylation, the thermodynamics of the four‐step oxygen evolution reaction (OER) mechanism are examined in detail for different models of the α‐Fe2O3 (0001) and (102) surfaces. Importantly, the results underline that the nature of the surface termination and the degree of near‐surface hydroxylation give rise to significant variations in the OER overpotentials. 相似文献
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Michelle P. Browne Jan Plutnar Amir Masoud Pourrahimi Zdenek Sofer Martin Pumera 《Liver Transplantation》2019,9(26)
3D‐printing technologies have begun to revolutionize many manufacturing processes, however, there are still significant limitations that are yet to be overcome. In particular, the material from which the products are fabricated is limited by the 3D‐printing material precursor. Particularly, for photoelectrochemical (PEC) energy applications, the as‐printed electrodes can be used as is, or modified by postfabrication processes, e.g., electrochemical deposition or anodization, to create active layers on the 3D‐printed electrodes. However, the as‐printed electrodes are relatively inert for various PEC energy applications, and the aforementioned postfabrication processing techniques do not offer layer conformity or control at the Ångström/nano level. Herein, for the first time, atomic layer deposition (ALD) is utilized in conjunction with metal 3D‐printing to create active electrodes. To illustrate the proof‐of‐concept, TiO2 is deposited by ALD onto stainless steel 3D‐printed electrodes and subsequently investigated as a photoanode for PEC water oxidation. Furthermore, by tuning the TiO2 thickness by ALD, the activity can be optimized. By combining 3D‐printing and ALD, instead of other metal deposition techniques, i.e., sputtering, rapid prototyping of electrodes with controllable thickness of the desired material onto an as‐printed electrodes with any porosity can be achieved that can benefit a multitude of energy applications. 相似文献
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Alejandro Martinez‐Garcia Harry B. Russell William Paxton Srikanth Ravipati Sonia Calero‐Barney Madhu Menon Ernst Richter James Young Todd Deutsch Mahendra K. Sunkara 《Liver Transplantation》2018,8(16)
Here, unbiased water splitting with 2% solar‐to‐hydrogen efficiency under AM 1.5 G illumination using new materials based on GaSb0.03P0.97 alloy is reported. Freestanding GaSbxP1?x is grown using halide vapor phase epitaxy. The native conductivity type of the alloy is modified by silicon doping, resulting in an open‐circuit potential (OCP) of 750 mV, photocurrents of 7 mA cm?2 at 10 sun illumination, and corrosion resistance in an aqueous acidic environment. Alloying GaP with Sb at 3 at% improves the absorption of high‐energy photons above 2.68 eV compared to pure GaP material. Electrochemical Impedance Spectroscopy and illuminated OCP measurements show that the conduction band of GaSbxP1?x is at ?0.55 V versus RHE irrespective of the Sb concentration, while photocurrent spectroscopy indicates that only radiation with photon energies greater than 2.68 eV generate mobile and extractable charges, thus suggesting that the higher‐laying conduction bands in the Γ 1 valley of the alloys are responsible for exciton generation. 相似文献
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Photoelectrochemical (PEC) water splitting represents an environmentally friendly and sustainable method to obtain hydrogen fuel. Semiconductor materials as the central components in PEC water splitting cells have decisive influences on the device's solar‐to‐hydrogen conversion efficiency. Among semiconductors, metal oxides have received a lot of attention due to their outstanding (photo)‐electrochemical stability, low cost, favorable band edge positions and wide distribution of bandgaps. In the past decades, significant processes have been made in developing metal oxide nanomaterials for PEC water splitting. In this review, the recent progress using metal oxides as photoelectrodes and co‐catalysts for PEC water splitting is summarized. Their performance, limitations and potentials are also discussed. Last, the key challenges and opportunities in the development and implementation of metal oxide nanomaterials for PEC water splitting are discussed. 相似文献
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Angela Y. Chang Yi‐Ju Cho Kuan‐Chen Chen Chang‐Wen Chen Alper Kinaci Benjamin T. Diroll Michael J. Wagner Maria K. Y. Chan Hao‐Wu Lin Richard D. Schaller 《Liver Transplantation》2016,6(15)
Carrier dynamics in methylammonium lead halide (CH3NH3PbI3–xClx) perovskite thin films, of differing crystal morphology, are examined as functions of temperature and excitation wavelength. At room temperature, long‐lived (>nanosecond) transient absorption signals indicate negligible carrier trapping. However, in measurements of ultrafast photoluminescence excited at 400 nm, a heretofore unexplained, large amplitude (50%–60%), 45 ps decay process is observed. This feature persists for temperatures down to the orthorhombic phase transition. Varying pump photon energy reveals that the fast, band‐edge photoluminescence (PL) decay only appears for excitation ≥2.38 eV (520 nm), with larger amplitudes for higher pump energies. Lower photon‐energy excitation yields slow dynamics consistent with negligible carrier trapping. Further, sub‐bandgap two‐photon pumping yields identical PL dynamics as direct absorption, signifying sensitivity to the total deposited energy and insensitivity to interfacial effects. Together with first principles electronic structure and ab initio molecular dynamics calculations, the results suggest the fast PL decay stems from excitation of high energy phonon modes associated with the organic sub‐lattice that temporarily enhance wavefunction overlap within the inorganic component owing to atomic displacement, thereby transiently changing the PL radiative rate during thermalization. Hence, the fast PL decay relates a characteristic organic‐to‐inorganic sub‐lattice equilibration timescale at optoelectronic‐relevant excitation energies. 相似文献
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Pongkarn Chakthranont Thomas R. Hellstern Joshua M. McEnaney Thomas F. Jaramillo 《Liver Transplantation》2017,7(22)
Tandem photoelectrochemical water splitting cells utilizing crystalline Si and metal oxide photoabsorbers are promising for low‐cost solar hydrogen production. This study presents a device design and a scalable fabrication scheme for a tandem heterostructure photoanode: p+n black silicon (Si)/SnO2 interface/W‐doped bismuth vanadate (BiVO4)/cobalt phosphate (CoPi) catalyst. The black‐Si not only provides a substantial photovoltage of 550 mV, but it also serves as a conductive scaffold to decrease charge transport pathlengths within the W‐doped BiVO4 shell. When coupled with cobalt phosphide (CoP) nanoparticles as hydrogen evolution catalysts, the device demonstrates spontaneous water splitting without employing any precious metals, achieving an average solar‐to‐hydrogen efficiency of 0.45% over the course of an hour at pH 7. This fabrication scheme offers the modularity to optimize individual cell components, e.g., Si nanowire dimensions and metal oxide film thickness, involving steps that are compatible with fabricating monolithic devices. This design is general in nature and can be readily adapted to novel, higher performance semiconducting materials beyond BiVO4 as they become available, which will accelerate the process of device realization. 相似文献
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Barium Bismuth Niobate Double Perovskite/Tungsten Oxide Nanosheet Photoanode for High‐Performance Photoelectrochemical Water Splitting 
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下载免费PDF全文 Baicheng Weng Corey R. Grice Jie Ge Tilak Poudel Xunming Deng Yanfa Yan 《Liver Transplantation》2018,8(10)
Recently, a new method to effectively engineer the bandgap of barium bismuth niobate (BBNO) double perovskite was reported. However, the planar electrodes based on BBNO thin films show low photocurrent densities for water oxidation owing to their poor electrical conductivity. Here, it is reported that the photoelectrochemical (PEC) activity of BBNO‐based electrodes can be dramatically enhanced by coating thin BBNO layers on tungsten oxide (WO3) nanosheets to solve the poor conductivity issue while maintaining strong light absorption. The PEC activity of BBNO/WO3 nanosheet photoanodes can be further enhanced by applying Co0.8Mn0.2Ox nanoparticles as a co‐catalyst. A photocurrent density of 6.02 mA cm?2 at 1.23 V (vs reversible hydrogen electrode (RHE)) is obtained using three optically stacked, but electrically parallel, BBNO/WO3 nanosheet photoanodes. The BBNO/WO3 nanosheet photoanodes also exhibit excellent stability in a high‐pH alkaline solution; the photoanodes demonstrate negligible photocurrent density decay while under continuous PEC operation for more than 7 h. This work suggests a viable approach to improve the PEC performance of BBNO absorber‐based devices. 相似文献
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Water Splitting: The “Midas Touch” Transformation of TiO2 Nanowire Arrays during Visible Light Photoelectrochemical Performance by Carbon/Nitrogen Coimplantation (Adv. Energy Mater. 20/2018) 下载免费PDF全文
下载免费PDF全文 Xianyin Song Wenqing Li Dong He Hengyi Wu Zunjian Ke Changzhong Jiang Gongming Wang Xiangheng Xiao 《Liver Transplantation》2018,8(20)
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Huan Li Yitong Zhou Ming Zhao Bo Jin Zi Wen Haiming Xie Shixue Dou Qing Jiang 《Liver Transplantation》2020,10(3)
The development of lithium–sulfur batteries is limited by the poor conductivity of sulfur cathodes and soluble long‐chain lithium polysulfides (LPSs), which cause the low utilization of sulfur and the aversive shuttle effect, and further, give rise to self‐discharge, rapid reversible capacity fading, and low Coulombic efficiency. In this work, a novel configuration is built for high‐performance lithium–organosulfur batteries, in which the organosulfur hybrid material and lithium metal are used as the cathode and the anode, respectively, and are separated by a functional separator decorated with nitrogen and sulfur co‐doped reduced graphite oxide. The organosulfur in the cathode prevents the shuttle effect by inhibiting the formation of long‐chain LPSs. In addition, the functional separator effectively adsorbs LPSs escaping from the cathode by electrostatic interactions and further restrains the shuttle effect. These effects are confirmed by density‐functional theory calculations. As a result, this novel configuration provides a high initial discharge capacity of 1364 mAh g?1 at 0.2 C and a high discharge capacity of 750 mAh g?1 at 1 C after 700 cycles with a very low capacity decay rate of 0.037% per cycle. 相似文献
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Jingshan Luo Zhen Li Shiro Nishiwaki Marcel Schreier Matthew T. Mayer Peter Cendula Yong Hui Lee Kunwu Fu Anyuan Cao Mohammad Khaja Nazeeruddin Yaroslav E. Romanyuk Stephan Buecheler S. David Tilley Lydia Helena Wong Ayodhya N. Tiwari Michael Grätzel 《Liver Transplantation》2015,5(24)
Efficient sunlight‐driven water splitting devices can be achieved by pairing two absorbers of different optimized bandgaps in an optical tandem design. With tunable absorption ranges and cell voltages, organic–inorganic metal halide perovskite solar cells provide new opportunities for tailoring top absorbers for such devices. In this work, semitransparent perovskite solar cells are developed for use as the top cell in tandem with a smaller bandgap photocathode to enable panchromatic harvesting of the solar spectrum. A new CuInxGa1‐xSe2 multilayer photocathode is designed, exhibiting excellent performance for photoelectrochemical water reduction and representing a near‐ideal bottom absorber. When pairing it below a semitransparent CH3NH3PbBr3‐based solar cell, a solar‐to‐hydrogen efficiency exceeding 6% is achieved, the highest value yet reported for a photovoltaic–photoelectrochemical device utilizing a single‐junction solar cell as the bias source under one sun illumination. The analysis shows that the efficiency can reach more than 20% through further optimization of the perovskite top absorber. 相似文献