Fotoelettrolisi - Acqua Sole Idrogeno Ossigeno, Copper gallium diselenide photocathodes for solar photoelectrolysis

Semiconductor Materials for Photoelectrolysis.pdf NREL
John A. Turner, Todd G. Deutsch, Huyen Dinh, 19 Maggio 2009

• L'obiettivo di questo lavoro è quello di scoprire e caratterizzare una serie di materiali semiconduttori o di configurazione del dispositivo che (i) divida l'acqua in idrogeno e ossigeno spontaneamente su illuminazione

The objective of this work is to discover and characterize a semiconductor material set or device configuration that (i) splits water into hydrogen and oxygen spontaneously upon illumination, (ii) has a solar-to-hydrogen efficiency of at least 5% with a clear pathway to a 10% water splitting system, (iii) exhibits the possibility of 1000 hrs stability under solar conditions and (iv) can be adapted to volume-manufacturing techniques.
• The main focus of our work this past year has been to develop and optimize state-of-the-art materials that we have identified as promising for meeting DOE’s near-term efficiency and durability targets.


The Cu-Ga-Se layer depicted above was synthesized from an electrolytic bath made with 1.36 mM of Cu(NO3)2, 10 mM of Ga(NO3)3, 8 mM of H2SeO3, and 1 M of LiNO3. The applied potential was -0.6V vs Pt, over 30 min at room temperature.



We initiated studies on platinum surface catalyst optimization for maximizing cathodic photocurrent on p-type GaInP2, Ga(In)PN, and (in collaboration with the University of Hawaii) CGS electrodes. The two techniques we are studying are electrodeposition from chloroplatinic acid and adsorption of Pt colloids from neutral solutions. Platinum has been observed on electrode surfaces by SEM and the chemical signature detected by EDS. Pt increased the magnitude of photocurrent and shifted the onset to lower potentials indicating catalysis. We plan to adapt the catalyst treatment for other materials.

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Solar Hydrogen and Nanotechnology II (Conference Proceedings)
Editor(s): Jinghua Guo
11 Settembre 2007
[Ricerca su SPIE (Advancing light-based research): Solar Hydrogen and Nanotechnology]

Tavola dei Contenuti





Paper Abstract
Copper chalcopyrite films exhibit properties suitable for solar energy conversion processes such as direct bandgap, and excellent carrier transport. To explore the possibilities of solar-powered hydrogen production by photoelectrolysis using these materials, we have synthesized p-type polycrystalline CuGaSe2 films by vacuum co-evaporation of the elemental constituents, and performed physical and electrochemical characterizations of the resulting films and electrodes. Based on CuGaSe2 material with 1.65 eV bandgap, a 2.2 micron thick electrode exhibited an outdoor 1-sun photocurrent of 16 mA/cm2, while a 0.9 micron thin device still produced 12.6 mA/cm2 in conjunction with vigorous gas evolution. Flatband potential measurements and bias voltage requirements for saturation photocurrents indicate a valence band position to high for practical device implementation. Future photoelectrolysis devices may be based on copper chalcopyrites with lower valence band maximum in conjunction with a suitable auxiliary junction.

Le pellicole di Calcopirite di Rame esibiscono proprieta' appropriate per processi di conversione ad energia solare, come il bandgap diretto (rilascio diretto di elettroni dall'atomo), ed eccellente vettore di trasporto. Al fine di esplorare le possibilita' della produzione di Idrogeno direttamente dal sole attraverso la foto elettrolisi, usando questi materiali, abbiamo sintetizzato una pellicola policristallina di tipo P CuGaSe2 (Rame, Gallio, Selenio) tramite co evaporazione degli elementi costituenti, e praticato delle caratterizzazioni fisiche ed elettrochimiche della pellicola risultante e degli elettrodi. Basandoci sui materiali di CuGaSe2 con una banda di valenza di 1.65 eV, a 2.2 micron di spessore, questo dispositivo produce una corrente di 12.6 mA/Cm2 (milli ampere a centimetro quadrato) unito a vigorose evoluzioni di gas. Le misure di banda piatta potenziali e requisiti di tensione di deviazione per la corrente di saturazione indicano una banda di valenza troppo alta per implementazioni pratiche del dispositivo. I dispositivi di foto elettrolisi futuri, potranno essere basati sulla calcopirite di rame con un massimo di banda di valenza più basso, unitamente ad una giunzione ausiliare appropriata.







Paper Abstract
Hydrogen production using water splitting by photoelectrochemical solar cells equipped with a TiO2 photoelectrode has been attracting much attention. However, TiO2 encounters serious difficulty in achieving hydrogen evolution. One solution to this difficulty is using a hydrogen-producing semiconductor, such as silicon, and an oxidation reaction other than oxygen evolution, such as oxidation of iodide ions into iodine (triiodide ion). In this study, microcrystalline silicon (μc-Si:H) thin films are used as photoelectrodes in the photodecomposition of HI for low-cost and efficient production of solar hydrogen. An n-μc-3C-SiC:H and an i-μc-Si:H layer are deposited on glassy carbon substrates using the hot-wire cat-CVD method. The μc-Si:H electrodes are modified with platinum nanoparticles through electroless displacement deposition. The platinum nanoparticles improve the electrode's stability and catalytic activity. The electrodes produce hydrogen gas and iodine via photoelectrochemical decomposition of HI with no external bias under simulated solar illumination. We also attempt solar water splitting using a multi-photon system equipped with the μc-Si:H thin film and TiO2 photoelectrodes in series.







The sonoelectrochemical method is a highly efficient technique for the synthesis of well ordered and robust titanium dioxide nanotube arrays. Self ordered arrays of TiO2 nanotubes of various diameters and length can be rapidly synthesized under an applied potential of 5-20 V in the presence of organic electrolyte solvents like ethylene glycol. The TiO2 nanotubes prepared in the organic electrolytes and annealed under N2 atmospheres give a TiO2-xCx type of semiconductor materials having a band gap of 2.0 eV. The hybride nanotubes demonstrated promising efficiency in splitting water in the presence of solar light. In addition, the modeling of titania nanotubes using the first principles of the Density Functional Theory (DFT) approach is underway for calculating electronic properties of the TiO2 nanotubular structure. It is envisioned that the DFT modeling will yield valuable information in developing improved titania photoanodes for high efficiency photoelectrochemical splitting of water.
ITA: Il metodo sono-electro-chimico e' una tecnica estremamente efficiente per la sintesi di nanotubi robusti e ben ordinati di diossido di titanio. I nanotubi di TiO2 auto ordinati, di vari diametri e lunghezza, possono essere sintetizzati rapidamente sotto un potenziale applicato di 5-20 V, alla presenza di solventi elettrolitici organici come il glycol di etilene. I nanotubi di TiO2 preparati negli elettroliti organici e temperati in una atmosfera di N2 forniscono un tipo di materiale semiconduttore TiO2-xCx che hanno una banda di valenza di 2.0 eV. I nanotubi hybride dimostrarono un'efficienza promettente nel dividere l'acqua alla presenza di luce solare. In aggiunta, la modellazione dei nanotubi di titanio che usa l'approccio al primo principio della Teoria Funzionale di Densità (DFT), e' in preparazione per calcolare le proprietà elettroniche delle strutture nanotubolari di TiO2. Si prevede che la modellazione DFT produrrà informazioni preziose nello sviluppare foto anodi di titanio migliorati per la scissione fotoelettrochimica dell'acqua ad alta efficienza.










Paper Abstract
The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost system using the solar radiation in Yucatan, Mexico. A two-step process is necessary with a closed photobioreactor, in which the algae are firstly growth and then induced for hydrogen generation. Preliminary results are presented in this work with some planning for the future. Different culture broths, temperatures and light intensities were tested for biomass and hydrogen production in laboratory conditions. The first experiments in external conditions with solar radiation and without temperature control have been performed, showing the potential of this technique at larger scales. However, some additional work must be done in order to optimize the culture maintenance, particularly in relation with the temperature control, the light radiation and the carbon dioxide supply, with the idea of keeping an economic production.
ITA



Edited by fabrizio3 - 2/12/2011, 11:04

Concentrating Solar Hydrogen Generators
Generatori di Idrogeno a Concentrazione Solare combinato al Fotovoltaico
Nanoptek

Un sistema che utilizza un particolare fotoanodo brevettato, in grado di dissociare l'acqua in idrogeno e ossigeno, usando 1 terzo dell'energia elettrica necessaria, associando la luce solare concentrata in un fattore di 30x




Technology download

SHG300Photos.pdf Questo PDF contiene diverse immagini del nostro SHG300 ™, incompleto in confronto con la nostra SHG50.
VLTrev5.pdf Questo PDF contiene informazioni sui nostri foto-catalitico luce visibile ™ e ™ Sunblock avanzata.
SHG300EESrev3.pdf Questo PDF si concentra sull'applicazione immagazzinamento dell'energia elettrica per i nostri SHG300 ™.
SHG50GC.pdf Questo PDF è prodotto di letteratura per il nostro SHG50 ™.
SHG300rev2.pdf Questo PDF è prodotto di letteratura per il nostro SHG300 ™.
Nanoptek Corporation Rev1.ppt Questa è una panoramica della tecnologia di Nanoptek.
Nanoptek Riflettore 3a.wmv Questa e' un'animazione, creata da C. Chamberlain, è un vecchio prototipo di concentrazione ed è inclusa qui solo per divertimento.


Brevetti
U.S. Patent No. 7,485,799
U.S. Patent No. 7,628,928
U.S. Patent No. 7,947,221
U.S. Patent No. 7,992,528
U.S. Patent No. 7,995,871
Nine (9) additional U.S. and International patents pending and/or applied for
Nine (9) licensed patents

Pubblicazioni:

Guerra, J. M., “Efficient Hybrid Solar Hydrogen Generator,”.pdf Cryogas International, Vol. 49, No. 2, pp. 42-44. February 2011
Lukas Thulin and John Guerra, “Calculations of strain-modified anatase TiO2 band structures,” Physical Review B 77, 195112 (2008)
J.M. Guerra, L. Thulin, D. Vezenov et al, “Embedded nano-optic media for near-field high density optical data storage: modeling, fabrication, and performance,” Proceedings, Optical Data Storage Conference, SPIE, April, 2001.
J. M. Guerra, L/ Thulin, D. Vezenov et al, “Near-field optical recording without low-flying heads,” ISOM Technical Digest, Taipei, 2001.
J. M. Guerra, L. Thulin, D. Vezenov et al, “Near-field optical recording without low-flying heads: Integral Near-Field Optical (INFO) Media,” Japanese Journal of Applied Physics, Vol. 41 (2002) pp. 1866-1875 Pt. 1, No. 3B, March, 2002.
Guerra, J. M., “Photon tunneling microscopy,” in Proceedings from Surface Measurement and Characterization Meeting, Hamburg, SPIE Vol. 1009, pp. 254-262, 1988.
Guerra, J. M., “Photon tunneling microscope,” Paper Summaries, SPSE 42nd Annual Conference, Boston, pp. 11-15, 1989.
Guerra, J. M., “Photon tunneling microscopy,” Applied Optics, Vol. 29, No. 26, pp. 3741-3752, 1990.
Guerra, J. M., “Photon tunneling microscopy of polymers,” IS&T 46th Annual Conference Advance Printing of Paper Summaries, Cambridge, Mass., pp. 62-66, 1993.
Guerra, J. M., “Photon tunneling microscopy of diamond-turned surfaces,” Applied Optics, Vol. 32, No.1, pp. 24-26, 1993.
Guerra, J. M., Srinivasarao, M., Winter, H. H., Stein, R. S., “Photon Tunneling Microscopy,” Polymer Preprints (April 1992), Vol. 33.
Guerra, J. M., Srinivasarao, M., and Stein, R., “Photon tunneling microscopy of polymeric surfaces,” Science, Vol. 262, pp. 1395-1400, 1993.
Guerra, J. M., Srinivasarao, M., and Winter, H., “Photon tunneling microscopy of single crystals of polypropylene,” Polymer, April, 1994.
Guerra, J. M., Hsieh, A., and Srinivasarao, M., “Photon tunneling microscopy of polymers,” AFM/STM Conference (1993), Natick Army Labs., Natick, Mass. In: Atomic Force Microscopy/ Scanning Tunneling Microscopy, Edited by S. Cohen, M. Bray, and M. Lightbody, Plenum Press, 1994.
Guerra, J. M., “Photon tunneling microscopy applications.” In: Materials Research Society Symposium Proceedings: Determining Nanoscale Physical Properties of Materials by Microscopy and Spectroscopy, Vol. 332: 449-460, M. Sarikaya, H. K. Wickramasinghe and M. Isaacson, eds. 1994.
Guerra, J. M., “Super-resolution through Diffraction-born Evanescent Waves,” Appl. Phys. Lett. 66 (26), p. 3555. 1995.
J. M. Guerra and G. K. Menon, “Photon Tunneling Microscopy: A New Technique for Imaging Stratum Corneum,” The Journal of Investigative Dermatology, To be published.
J. M. Bennett, Y. Namba, J. M. Guerra, J. Jahanmir, T. L. Balter, and J. C. Podlesny, “Topographic Measurements of Precision Ground Optical Glasses,” Applied Optics, Vol. 36, (10) p. 2211-2216, 1997.
K. Goyal, J. D. Bhawalker, Y. Conturie, P. Gavrilovic, Y. Mao, H. Po, and J. Guerra, “High beam quality of ultraviolet radiation generated through resonant enhanced frequency doubling of a diode laser,” J. Opt. Soc. Am. B, Vol. 16, No. 12, Dec. 1999. P. 2207-2216.
Guerra, J. M., Photon Tunneling Microscopy: Seeing in Forbidden Light, Kluwer Academic Publishers, Dordrecht (in preparation).

Lavori in cui si fa' riferimento:

Characterization of Optical Thin Films (D. Smith, Institute of Optics, 1991).
Collier’s Encyclopedia Yearbook of 1993 (P. F. Collier, 1994).
Atomic Force Microscopy/Scanning Tunneling Microscopy, (S. Cohen, M. Bray, and M. Lightbody, Eds., Plenum Press, 1994).
Determining Nanoscale Physical Properties of Materials by Microscopy and Spectroscopy, (M. Sarikaya, H. K. Wickramasinghe and M. Isaacson, Eds., Materials Research Society Symposium Proceedings, 1994).
Surface Analysis of Paper (T. Connors, S. Banerjee, Eds., CRC Press, 1995).
Near-Field Optics (M. A. Paesler and P. J. Moyer, Wiley Interscience, 1996).
Optical Methods in Surface Metrology (D. J. Whitehouse, S.P.I.E.’s Milestone Series of Selected Reprints, 1996: three papers selected).
Near Field Optics and Nanoscopy (J. P. Fillard, Scientific World Co., 1998).
Handbook of Physical Vapor Deposition (PVD) Processing (D. M. Mattox, Noyes Publications, 1998).
Near-Field Nano-Optics (M. Ohtsu and H. Hori, Kluwer Academic / Plenum Publishers, 1999).
Evanescent Waves from Newtonian Optics to Atomic Optics (F. deFornel, Springer, 2000).
Comprehensive Polymer Science, (second supplement, M. Srinivasarao, “Recent Advances in Microscopy,” Pergamon Press, in press).
Photonics for Fiber and Integrated Optics (K. Iizuka, Wiley, July, 2001).
Near Field Optics (S. Jutamulia, S.P.I.E.’s Milestone Series of Selected Reprints, 2001.
Near-Field Optics and Surface Plasmon Polaritons (S. Kawata, Ed., Topics in Applied Physics, Vol. 81, Springer, 2001).
Care of Astronomical Telescopes and Accessories (M. Barlow Pepin, Patrick Moore’s Practical Astronomy Series, Springer, 2004).
Multi-Modality Microscopy (H. Yu, P. Cheng, P. Lin, and F. Kao Eds., World Scientific, 2006).

Edited by fabrizio3 - 20/10/2011, 16:24

NREL Photoelectrolysis

This is a GaInP2/GaAs tandem semiconductor splitting water with no applied bias. Electrode is short circuited to a RuO2 coated platinum electrode in a 0.5M H2SO4 electrolyte. Hydrogen can be seen evolving from the semiconductor surface after it is connected to the counter electrode where oxygen is produced. The first portion was taken under ~10sun illumination from a xenon lamp, the second portion is outdoors in Golden, CO in early March 2011. For more info see Science 280, p425 (1998) and NREL. Hydrogen Production and Delivery.
Credits: John Turner, Todd Deutsch, Adam Welch, James Young, John Geisz


Solar Thermal Water Splitting
Dissociazione Solare Termica dell'Acqua

Scienziati dell'NREL hanno dimostrato che la luce solare ad alta concentrazione può essere utilizzata per generare le alte temperature necessarie per scindere il metano in Idrogeno e Carbonio. L'energia solare con centrata può anche essere usata per generare temperature di diverse centinaia di gradi fino a 2.000 gradi, in cui i cicli di reazione termochimica possono essere usati per produrre idrogeno. Queste alte temperature, processi termochimici guidati da elevati flussi solari, offrono un nuovo approccio per la produzione eco-compatibile di idrogeno. Il ritmo di reazione molto elevato, a queste alte temperature, danno luogo a tassi di reazione molto veloci che esaltano i tassi di produzione in maniera significativa e compensano superandola, la natura intermittente della risorsa solare.

Presentazioni e pubblicazioni relative:
. Development of a Solar-Thermal ZnO.Zn Water Splitting Thermochemical Cycle.pdf. A.W. Weimer, C. Perkins, P. Lichty, H. Funke, J. Zartman, D. Hirsch, C. Bingham, A. Lewandowski, S. Haussener, and A. Steinfeld. (April 2009)
. Solar Thermal Reactor Materials Characterization.pdf. P.R. Lichty, A.M. Scott, C.M. Perkins, C. Bingham, and A.W. Weimer. (February 2008)






Edited by fabrizio3 - 20/10/2011, 17:07