Aminoalkanoic Acids as Alternatives to Mercaptoalkanoic Acids for the Linker-Assisted Attachment of Quantum Dots to TiO<sub>2</sub>

Rivera-González, Natalia; Chauhan, Saurabh; Watson, David F.

doi:10.1021/acs.langmuir.6b02704

Cited by 13 publications

(7 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…QDs‐based photoelectrodes can be fabricated using a number of methods, such as successive ionic layer adsorption and reaction (SILAR), [ 59 ] chemical bath deposition (CBD), [ 36d,59b,60 ] electrophoretic deposition, [ 46,61 ] direct adsorption [ 62 ] and linker‐assisted assembly. [ 63 ] QDs may adsorb on the surface of nanotubes, [ 64 ] nanorods [ 45a ] or in the pores of mesoporous thin films, [ 65 ] depending on the size, shape, surface of QDs, and morphology of the host semiconductors. The host semiconductor works as a scaffold for the QDs and simultaneously as a charge acceptor, using the band shift between the QDs and the host material as a driving force to achieve efficient charge separation, as shown in Figure 2e.…”

Section: Qds‐based Pec Systemmentioning

confidence: 99%

“…For instance, a bifunctional linker called MAA ( Figure 7 a) was developed to anchor colloidal CdSe QDs onto NiO films. [ 63b ] The HOMO energy level of MAA (≈0.8 V vs NHE) is more negative than the VB of CdSe QDs (2.0 nm in diameter, ≈1.23 V vs NHE), while more positive than the VB of NiO (≈0.5 V vs NHE), making MAA as a relay to facilitate the hole transfer from the VB of CdSe QDs to NiO at the interface of the integrated CdSe/MAA/NiO photocathode. Upon illumination, the photocurrent density was as high as −60 µA cm −2 at a bias of −0.1 V versus NHE in 0.1 m Na 2 SO 4 (pH = 6.8), which remained unchanged even after 45 h. An electron‐rich heterocyclic structured phenothiazine (PTZ) ligand was then developed to construct CdSe/PTZ/NiO photocathode through a simple solution‐processed method thanks to its highest occupied molecular orbital level (HOMO, ≈0.9 V vs NHE).…”

Section: Qds‐based Pec Systemmentioning

confidence: 99%

Section: Qds‐based Pec Systemmentioning

confidence: 99%

See 2 more Smart Citations

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Liu

Zhao

Wang

et al. 2021

Advanced Energy Materials

View full text Add to dashboard Cite

opportunity since it is by far the most abundant, sustainable, carbon-neutral, and inexpensive energy source. The theoretical potential of solar power striking the earth's surface is ≈89 300 TW (the integral of the time-and-space-averaged solar flux 342.5 W m −2 over the earth's surface area 5.11 × 10 14 m 2 , estimating that ≈30% and ≈19% are scattered and absorbed by the atmosphere and clouds), [3] which is equivalent to ≈6000 times the power used worldwide every year (estimated at 13.5 TW in 2001, with projected growth up to 27.6 TW by 2050 by the Intergovernmental Panel on Climate Change). [4] In particular, storing solar energy in the form of H 2 presents advantages such as high energy content per mass (143 MJ kg −1), ease of transportation, and cost-effectiveness, [5] thereby addressing the storage challenge which is associated with the diffuse and intermittent character of solar irradiation. Solar energy and water could be converted into H 2 [5b] indirectly by using solar-converted electricity and an electrolyzer, [6] concentrated solar thermal and an electrolyzer, [7] biological and thermochemical processes [8] or directly by photo-/photoelectrocatalysis of water. [1b,f,g] The combination of the energy conversion step with electrolyzers is always limited by the performance of the electrolyzers, whose typical commercial efficiencies are around 73%. [9] Besides, indirect technologies suffer from excessive cost, area requirements, feasibility issues, or energy loss. [10] An alternative direct route is the photo-/photoelectrocatalysis of water, including powdered photocatalysts [11] and photoelectrochemical (PEC) cells. [12] The dispersion of powdered photocatalysts in water is suitable for large-scale processes, while the system requires stirring during the reaction and product separation after the reaction. In comparison, PEC systems (Figure 1a), which combine harvesting solar energy with water reduction into a single device, possesses several advantages. [13] i) PEC reactions address the issue of gas separation by generating products at different electrodes. ii) An external bias supply or self-bias voltage in the PEC system can provide additional energy input to compensate for the potential deficiency, [14] leading to the formation of a surface space charge layer and achieving efficient charge separation and an increased number of long-living photogenerated charges. [15] iii) Moreover, PEC systems can potentially be operated using only stable and abundant materials, such as Cu-based metal oxides, [16] Fe 2 O 3 , [14b,17] and TiO 2. [18] In a typical PEC system, at least one photoelectrode is used as a working electrode to harvest solar radiation, either acting Solar-driven photoelectrochemical (PEC) hydrogen evolution is a promising and sustainable approach to convert solar energy into a fuel that can be stored. Semiconductor quantum dots (QDs) are increasingly used in PEC devices due to their broad composition/size/shape tunable absorption spectrum (from ultraviolet to near-infrared, with significant over...

show abstract

Section: Qds‐based Pec Systemmentioning

confidence: 99%

Section: Qds‐based Pec Systemmentioning

confidence: 99%

See 1 more Smart Citation

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Liu

Zhao

Wang

et al. 2021

Advanced Energy Materials

View full text Add to dashboard Cite

show abstract

“…Thus, ν as (CO 2 – ) and ν s (CO 2 – ) are located at 1610 and 1382 cm –1 , respectively (see Figure S1B). This carboxylic-to-carboxylate conversion is very common in carboxylic acid coordination processes . The absence of the wide ν(OH), centered at 3000 cm –1 in the AuNP-L-TiO 2 NPs spectra supports this statement.…”

Section: Resultsmentioning

confidence: 70%

Synthesis of Au Nanoparticles Assisted by Linker-Modified TiO₂ Nanoparticles

et al. 2018

View full text Add to dashboard Cite

Plasmonic nanoparticles, especially gold ones, have been widely employed as photosensitizers in photoelectrovoltaic or photocatalytic systems. To improve the system's performance, a greater interaction of the nanoparticles with the semiconductor, generally TiO, is desired. Moreover, this performance is enhanced when an efficient covering of TiO surface by the sensitizer is achieved. The Brust-Schiffrin-like methods are of the most employed approaches for nanoparticles synthesis. In a traditional approach, the reduction of the gold precursor is performed in the presence of a stabilizer (typically a thiol molecule) free in solution. A second step in which the obtained nanoparticles are anchored to the semiconductor surface is necessary in the case of photosensitive applications. Drawbacks like steric hindrance turn more difficult the covering of the semiconductor's surface by nanoparticles. In this paper, we report a variation of this methodology, where the linker is previously anchored to the TiO nanoparticles surface. The resulting system is employed as the stabilizer in the gold reduction step. This strategy is carried out in aqueous media in two simple steps. A great covering of the titania surface by gold nanoparticles is achieved in all cases and the gold nanoparticles in the resulting nanoaggregate might be useful for photoelectrovoltaic or photocatalytic applications.

show abstract

“…The maximum effective and uniform surface area that can be obtained for application in a device depends on the surface wettability, solution properties, impingement conditions, and substrate vibration. It is wise to note that the quality of the resulting heterostructured material, both in dispersed and in deposited form, is significantly affected by such factors as the affinity of heterostructure components (the values of surface free energy, adhesion, surface wettability) [44,55,80], the roughness of the substrate or previously formed layer or component, the formation of the intermediate layer between different components [81], the acidicbasic conditions of the reaction media (especially for the components of heterostructure with different points of zero charge) [29,64,71], the reaction temperature [24,82], the organic binder, surfactant and organic solvent (mainly in the synthesis from solutions, for example, in solvothermal technology) [76,80,[82][83][84], etc.…”

Section: How Photoactive Heterostructures Are Madementioning

confidence: 99%

Photoactive Heterostructures: How They Are Made and Explored

et al. 2021

View full text Add to dashboard Cite

In our review we consider the results on the development and exploration of heterostructured photoactive materials with major attention focused on what are the better ways to form this type of materials and how to explore them correctly. Regardless of what type of heterostructure, metal–semiconductor or semiconductor–semiconductor, is formed, its functionality strongly depends on the quality of heterojunction. In turn, it depends on the selection of the heterostructure components (their chemical and physical properties) and on the proper choice of the synthesis method. Several examples of the different approaches such as in situ and ex situ, bottom-up and top-down, are reviewed. At the same time, even if the synthesis of heterostructured photoactive materials seems to be successful, strong experimental physical evidence demonstrating true heterojunction formation are required. A possibility for obtaining such evidence using different physical techniques is discussed. Particularly, it is demonstrated that the ability of optical spectroscopy to study heterostructured materials is in fact very limited. At the same time, such experimental techniques as high-resolution transmission electron microscopy (HRTEM) and electrophysical methods (work function measurements and impedance spectroscopy) present a true signature of heterojunction formation. Therefore, whatever the purpose of heterostructure formation and studies is, the application of HRTEM and electrophysical methods is necessary to confirm that formation of the heterojunction was successful.

show abstract

Aminoalkanoic Acids as Alternatives to Mercaptoalkanoic Acids for the Linker-Assisted Attachment of Quantum Dots to TiO₂

Cited by 13 publications

References 76 publications

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Synthesis of Au Nanoparticles Assisted by Linker-Modified TiO₂ Nanoparticles

Photoactive Heterostructures: How They Are Made and Explored

Contact Info

Product

Resources

About

Aminoalkanoic Acids as Alternatives to Mercaptoalkanoic Acids for the Linker-Assisted Attachment of Quantum Dots to TiO2

Cited by 13 publications

References 76 publications

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Synthesis of Au Nanoparticles Assisted by Linker-Modified TiO2 Nanoparticles

Photoactive Heterostructures: How They Are Made and Explored

Contact Info

Product

Resources

About

Aminoalkanoic Acids as Alternatives to Mercaptoalkanoic Acids for the Linker-Assisted Attachment of Quantum Dots to TiO₂

Synthesis of Au Nanoparticles Assisted by Linker-Modified TiO₂ Nanoparticles