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TiO 2 single-crystal nanomaterials with highly reactive surfaces have attracted widespread attention due to their fundamental aspects and industrial applications. However, many previous studies have ignored the poor photoelectric efficiency of TiO 2 nanomaterials originating from a mismatch in the diffusion distance of electrons and holes as well as migration rates of holes and electrons. Therefore, suppression of hole migration could enhance the photoelectrochemical performance of TiO 2 . In this work, single-crystal anatase TiO 2 nanomaterials with (001) facets were successfully prepared. The results suggested that some (101) facets were retained by the modified fluoride ion crystal facet control process. Subsequently, fluorine-free and Au-containing crystal facets were obtained by annealing and electrochemical deposition. In addition, the propensity for adsorption of Au on a TiO 2 (101) surface was verified by first-principles quantum chemical calculations. Electrochemical impedance spectroscopy and UV− visible spectrophotometry showed the presence of a large area (001), conducive to better enzyme affinity. Biosensors prepared by carrier self-separation derived from natural different facets and Au nanoparticles (TiO 2 (001)/Au/GOx) achieved high sensitivities reaching 16.86 μA mM −1 cm −2 , an extended linear range (0.01−3 mM), and a low detection limit (0.83 μM). In summary, the proposed route allowed for the first time the use of nanocrystal engineering in the construction of glucose biosensors with satisfactory performances, which is promising for the future fabrication of high-performance biosensors.

Designing low-cost and efficient evaporation system to maximize solar energy utilization is of great importance for the emerging solar water purification technologies. Herein, we demonstrate a universal sandwich hydrogel by...

Developing stable photoelectrochemistry (PEC) glucose biosensors with high sensitivity and a low detection limit is highly desirable in the biosensor field. Herein, a highly sensitive and stable enzymatic glucose PEC biosensor is rationally designed and fabricated using a TiO2NTs/Au/Pt/GOx electrode. First, we prepared one-dimensional TiO2 nanotube arrays which could realize the orthogonalization of the light-incident direction and the carrier diffusion direction via anodization. Subsequently, we used the method of photoassisted deposition for anchoring Pt nanoparticles on TiO2NTs after electrodepositing Au nanoparticles. Among them, Au nanoparticles promote light absorption via the surface plasmon resonance effect and the separation of photogenerated carriers through forming a Schottky junction. Moreover, the Pt nanoparticles on the electrode surface can react with hydrogen peroxide (H2O2) generated from glucose (Glu) oxidation by glucose oxidase (GOx), accelerating the electron-transfer process during glucose oxidation and greatly improving the sensitivity of the glucose biosensor. As a result, TiO2NTs/Au/Pt/GOx exhibited excellent PEC performance, achieving a high sensitivity of 81.93 μA mM–1 cm–2 and a low detection limit (1.39 μM), far exceeding the performance of TiO2NTs/M/GOx (M = Au, Pt). Therefore, the introduction of Pt nanoparticles as active substances to promote enzymatic reactions is important for designing high-performance enzyme biosensors.

Hindering the recombination of a photogenerated carrier is a crucial method to enhance the photoelectrochemical performance of ZnO due to its high exciton binding energy. Herein, the intramolecular donor−acceptor compensated semiconductor ZnO (I-D/A ZnO), introducing C dopants and oxygen vacancies, was prepared with the assistance of ascorbic acid (AA). According to the DFT calculations, the asymmetry DOS could lead to the longer carrier lifetime and the smaller electron transfer resistance. Then, the photoelectrochemical biosensor toward glucose was regarded as a model to discuss the application of ZnO in biosensors. As a result, the biosensor based on I-D/A ZnO showed good performance with high sensitivity, low limit of detection, and fine anti-interference, meaning that I-D/A ZnO is a promising semiconductor for photoelectrochemical biosensors.