CdS-Modified TiO2 Nanotubes with Heterojunction Structure: A Photoelectrochemical Sensor for Glutathione

The formation of heterojunction structures can effectively prevent the recombination of photogenerated electron-hole pairs in semiconductors and result in the enhancement of photoelectric properties. Using TiO₂ nanotubes (prepared using the hydrothermal-impregnation method) as carriers, CdS-TiO₂NTs were fabricated as a photoelectrochemical (PEC) sensor, which can be used under visible light and can exhibit good PEC performance due to the existence of the heterojunction structure. The experimental results show that the prepared CdS-TiO₂NTs electrode had a linear response to 2-16 mM glutathione (GSH). The sensor's sensitivity and detection limit (LOD) were 102.9 µA·mM^-1 cm^-2 and 27.7 µM, respectively. Moreover, the biosensor had good stability, indicating the potential application of this kind of heterojunction PEC biosensor.

Platinum and Iridium Oxide Co-modified TiO2 Nanotubes Array Based Photoelectrochemical Sensors for Glutathione

Oriented TiO₂ nanotubes, which are fabricated by anodic oxidation method, are prospective in photoelectrochemical analysis and sensors. In this work, Pt and IrO₂ co-modified TiO₂ nanotubes array was prepared via a two-step deposition process involving the photoreductive deposition of Pt and chemical deposition of IrO₂ on the oriented TiO₂ nanotubes. Due to the improved separation of photo-generated electrons and holes, Pt-IrO₂ co-modified TiO₂ nanotubes presented significantly higher PEC activity than pure TiO₂ nanotubes or mono-modified TiO₂ nanotubes. The PEC sensitivity of Pt-IrO₂ co-modified TiO₂ nanotubes for glutathione was also monitored and good sensitivity was observed.

The Influence of Materials, Heterostructure, and Orientation for Nanohybrids on Photocatalytic Activity

In this work, different structures based on electrodeposited n-type ZnO nanorods and p-type Cu₂O, CuSCN, and NiO nanostructures are fabricated for the degradation of methyl orange (MO). The influence of materials, heterostructure, and orientation for nanohybrids on photocatalytic activity is discussed for the first time. The heterojunction structures show remarkable enhancement compared to the bare semiconductor. The morphology of nanostructure has mainly an influence on the photocatalytic activity. NiO has the highest catalytic activity among the four pristine semiconductor nanostructures of ZnO, Cu₂O, CuSCN, and NiO. The greatest enhancement of the photocatalytic activity is obtained using a ZnO/NiO (1 min) heterostructure attributed to the heterojunction structure and extremely higher specific surface area, which can degrade MO (20 mg/L) into colorless within 20 min with the fastest photocatalytic speed among homogeneous heterojunction structures. Meanwhile, the methodology and data analysis described herein will serve as an effective approach for the design of hybrid nanostructures for solar energy application, and the appropriate nanohybrids will have significant potential to solve the environment and energy issues.

Acetylenic carbon-rich frameworks on copper foam as conjugated polymer photocathodes for efficient and stable water reduction

A poly(1,3,5-triethynylbenzene) (PTEB) nanofiber is synthesized on a copper foam surface and presents a 100 times increased record-high photocathodic current density for efficient water reduction.

ZnO nanodisks decorated with Au nanorods for enhanced photocurrent generation and photocatalytic activity

AuNR-/ZnONDKs with AuNRs decorated on the surfaces of round ZnO disks demonstrate superior photocurrent generation properties and photodegradation efficiency.

ZnO nanowire arrays decorated with PtO nanowires for efficient solar water splitting

Vertically-oriented PtO nanowires have been selectively grown on ZnO nanowire arrays for the first time by a light-controlled method and were utilized as highly efficient OER cocatalysts for remarkably enhancing the PEC performance of water splitting.

Fabrication and behaviors of CdS on Bi2MoO6 thin film photoanodes

Most Bi-based photoelectrodes have suitable band gaps and can effectively promote hydrogen evolution from water splitting, but there are few studies up to now for simple preparation methods for Bi-based binary metal oxides as photoanodes.

Selectivity of quantum dot sensitized ZnO nanotube arrays for improved photocatalytic activity

QD-sensitized ZnO heterostructures with different kinds and cycles of QDs exhibit different photocatalytic activity and the selectivity of the best QDs sensitizing ZnO for high photocatalytic activity is realized.

Photoelectrochemical water splitting strongly enhanced in fast-grown ZnO nanotree and nanocluster structures

We demonstrate selective growth of ZnO branched nanostructures: from nanorod clusters (with branches parallel to parent rods) to nanotrees (with branches perpendicular to parent rods). The growth of these structures was realized using a three-step approach: electrodeposition of nanorods (NRs), followed by the sputtering of ZnO seed layers, followed by the growth of branched arms using hydrothermal growth. The density, size and direction of the branches were tailored by tuning the deposition parameters. To our knowledge, this is the first report of control of branch direction. The photoelectrochemical (PEC) performance of the ZnO nanostructures follows the order: nanotrees (NTs) > nanorod clusters (NCs) > parent NRs. The NT structure with the best PEC performance also possesses the shortest fabrication period which had never been reported before. The photocurrent of the NT and NC photoelectrodes is 0.67 and 0.56 mA cm^-2 at 1 V vs. Ag/AgCl, respectively, an enhancement of 139% and 100% when compared to the ZnO NR structures. The key reason for the improved performance is shown to be the very large surface-to-volume ratios in the branched nanostructures, which gives rise to enhanced light absorption, improved charge transfer across the nanostructure/electrolyte interfaces to the electrolyte and efficient charge transport within the material.

Ultra-thin coating of g-C3N4 on an aligned ZnO nanorod film for rapid charge separation and improved photodegradation performance

Aligned 1D ZnO/g-C₃N₄ films were fabricated by simple refluxing with thermal vapor condensation for rapid charge separation and recyclable test.

Construction of ZnO/Cu2SnS3 nanorod array films for enhanced photoelectrochemical and photocatalytic activity

ZnO nanorod array films grown on fluorine-doped tin oxide glass substrates were homogeneously coated with visible light responsive Cu₂SnS₃ nanoparticles through a controllable one-step electrodeposition process.

Bi2MoO6/BiVO4 heterojunction electrode with enhanced photoelectrochemical properties

Herein, we demonstrate the synthesis of a Bi₂MoO₆ nanorod array followed by the deposition of a BiVO₄ absorber layer.

Double-Shelled CdS- and CdSe-Cosensitized ZnO Porous Nanotube Arrays for Superior Photoelectrocatalytic Applications

The effective separation and transport of photoinduced electron-hole pairs in photoanodes is of great significance to photoelectrochemical and catalytic performance. Here, a facile and effective two-step strategy is developed to fabricate double-shelled ZnO/CdS/CdSe porous nanotube photoanodes from ZnO nanorod arrays (NRAs). Surprisingly, after the process of the deposition of CdS and CdSe, the ZnO nanorod arrays are partially dissolved, resulting in the formation of ZnO/CdS/CdSe porous nanotube arrays (NTAs). By virtue of their unique porous nanotube structure and cosensitization effect, the ZnO/CdS/CdSe porous NTAs show superior photoelectrochemical water-splitting performance and organic-pollutant-degradation ability under visible light irradiation, as well as excellent long-term photostability.