आरोप अलग Nanocrystals और उनके ठोस साधन के द्वारा सौर ऊर्जा संचयन
Summary
आरोप अलग अर्धचालक nanocrystal सौर ऊर्जा उत्पादन के लिए deployable कंपोजिट के विकास के लिए एक सामान्य रणनीति प्रस्तुत किया है. हम एक nanoparticle ज्यामिति में दाता स्वीकर्ता nanocrystal डोमेन के कि विधानसभा एक photocatalytic समारोह को जन्म देता है, जबकि दाता स्वीकर्ता nanocrystal फिल्मों के थोक heterojunctions फोटोवोल्टिक ऊर्जा रूपांतरण के लिए इस्तेमाल किया जा सकता है.
Abstract
Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials offering a superior control over the spatial distribution of charge carriers across material interfaces. As this study demonstrates, a combination of donor-acceptor nanocrystal (NC) domains in a single nanoparticle can lead to the realization of efficient photocatalytic1-5 materials, while a layered assembly of donor- and acceptor-like nanocrystals films gives rise to photovoltaic materials.
Initially the paper focuses on the synthesis of composite inorganic nanocrystals, comprising linearly stacked ZnSe, CdS, and Pt domains, which jointly promote photoinduced charge separation. These structures are used in aqueous solutions for the photocatalysis of water under solar radiation, resulting in the production of H2 gas. To enhance the photoinduced separation of charges, a nanorod morphology with a linear gradient originating from an intrinsic electric field is used5. The inter-domain energetics are then optimized to drive photogenerated electrons toward the Pt catalytic site while expelling the holes to the surface of ZnSe domains for sacrificial regeneration (via methanol). Here we show that the only efficient way to produce hydrogen is to use electron-donating ligands to passivate the surface states by tuning the energy level alignment at the semiconductor-ligand interface. Stable and efficient reduction of water is allowed by these ligands due to the fact that they fill vacancies in the valence band of the semiconductor domain, preventing energetic holes from degrading it. Specifically, we show that the energy of the hole is transferred to the ligand moiety, leaving the semiconductor domain functional. This enables us to return the entire nanocrystal-ligand system to a functional state, when the ligands are degraded, by simply adding fresh ligands to the system4.
To promote a photovoltaic charge separation, we use a composite two-layer solid of PbS and TiO2 films. In this configuration, photoinduced electrons are injected into TiO2 and are subsequently picked up by an FTO electrode, while holes are channeled to a Au electrode via PbS layer6. To develop the latter we introduce a Semiconductor Matrix Encapsulated Nanocrystal Arrays (SMENA) strategy, which allows bonding PbS NCs into the surrounding matrix of CdS semiconductor. As a result, fabricated solids exhibit excellent thermal stability, attributed to the heteroepitaxial structure of nanocrystal-matrix interfaces, and show compelling light-harvesting performance in prototype solar cells7.
Protocol
Discussion
यह अध्ययन यह दर्शाता है कि कैसे nanocrystals अकार्बनिक समग्र आर्किटेक्चर photoinduced के आरोप से एक स्थानिक जुदाई को प्राप्त करने के लिए नियोजित किया जा सकता है. विशेष रूप से, इन कंपोजिट दो डोमेन है, जो तब या तो photocatalytic या ?…
Disclosures
The authors have nothing to disclose.
Acknowledgements
हम सलाह और मूल्यवान विचार – विमर्श के लिए डॉ. फेलिक्स (BGSU) Castellano और एन.आर. नील स्वीकार करना चाहते हैं. हम कृतज्ञता obor "सामग्री नेटवर्क" कार्यक्रम और वित्तीय सहायता के लिए बॉलिंग ग्रीन स्टेट यूनिवर्सिटी को स्वीकार करते हैं. 1112227 – यह काम आंशिक रूप से पुरस्कार चे के तहत NSF द्वारा समर्थित किया गया.
Materials
| Name of the reagent | Company | Catalogue number | Comments (optional) |
| octadecylamine (ODA), 90% | Fisher | AC12932-0050 | |
| selenium (Se), 200 mesh | Acros | AC19807-2500 | |
| tri-n-octylphosphine (TOP), 97% | Strem | 15-6655 | Air Sensitive |
| diethyl zinc (Et2Zn), 10% by wt. | Aldrich | 22080 | Air Sensitive, Light Sensitive |
| methanol, 99.8%, anhydrous | Aldrich | 179337 | |
| toluene, 99.8%, anhydrous | Aldrich | 244511 | |
| tri-n-octylphosphine oxide (TOPO), 99% | Aldrich | 223301 | |
| n-octadecylphosphonic acid (ODPA), 98% | PCI Synthesis | 104224 | |
| hexylphosphonic acid (HPA), 98% | PCI Synthesis | 4721-24-8 | |
| cadmium oxide (CdO), 99.99% | Aldrich | 202894 | |
| sulfur (S), 99.999% | Acros | AC19993-0500 | Strong odor |
| 11-mercaptoundecanoic acid (MUA), 95% | Aldrich | 450561 | |
| potassium hydroxide (KOH) | Acros | AC13406-0010 | |
| chloroform | VWR | EM-CX1059-1 | |
| lead oxide (PbO), 99.999% | Aldrich | 32306-1KG | |
| 1-octadecene (ODE), 90% | Aldrich | O806-25ML | |
| oleic acid (OA), 90% | Aldrich | O1008-1G | |
| bis(trimethylsilyl) sulfide (TMS), synthetic grade | Aldrich | 283134-25G | Air sensitive, strong odor, highly reactive |
| acetone | EMD Chemicals | AX0118-2 | |
| cadmium acetate | Acros | AC31713-5000 | |
| sodium sulfide nonahydrate (Na2S•9H2O), 98% | Alfa Aesar | CB1100945 | Light sensitive |
| hexadecyltrimethyl ammonium bromide (CTAB), 99% | Sigma | H6269-100G | |
| oleylamine, 70% | Aldrich | O7805-5G | |
| diphenyl ether | Alpha Aesar | 101-84-8 | |
| 1,2-hexadecanediol | TCI | 6920-24-7 | |
| Pt (II) acetylacetonate, 97% | Aldrich | 282782-5G | |
| isopropanol, 99.8%, anhydrous | Acros | AC32696-0025 | |
| titanium tetrachloride (TiCl4), 99.9% | Aldrich | 697079-25G | Extremely air sensitive |
| titanium dioxide, DSL 90T | DyeSol | DSL 90T | |
| terpineol | MP Biomedical | 98-55-5 | |
| 3-mercaptopropionic acid (MPA), 99% | Alfa Aesar | A10435 | Strong odor |
| octane, anhydrous, 99% | Aldrich | 412236 |
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