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Dye-sensitized solar cells (DSSCs) are the third generation of solar cells. Compared with traditional silicon-based solar cells, DSSCs have the advantages of low cost, good flexibility, and sustainability. Photoanode, as the carrier of the electron transport layer and dye adsorption, plays a crucial role in DSSC. However, the conversion efficiency of single-layer structured photoanode is still low, and the short-circuit current density is small. To solve these problems, we carried out doping modification and structural optimization of the ZnO single-layer photoanode. The main work is as follows: 1) considering that the band gap of ZnO is 3.3 eV, the addition of Ag2O (1.2~1.5 eV) nanoparticles on the basis of single-layer ZnO thin films can reduce the band gap distance, and further improve the optical response of the material in the range of visible light; 2) using the plasmon effect, a small number of gold nanoparticles are inserted into the lattice of the main material to provide more free charge; 3) the use of natural dye sensitizers improves the photoelectric conversion efficiency of DSSC and reduces the overall cost. The results of material characterization and photoelectrochemical performance test show that the current density is increased by 176% and the photoelectric conversion efficiency is increased by 195%.

Materials with heterostructures that are sensitive to light have a wide range of applications in photoelectrochemical (PEC) detection and can improve their photoelectric performance. Here, we have designed a reliable and low-cost PEC biosensor applied for the detection and analysis of cold-resistant RNA in winter wheat. First, TiO2 nanospheres, a photoactive material, as well as NiO nanoflowers were prepared, and TiO2 was coupled with prepared NiO to form a compact heterojunction structure of NiO/TiO2, on which Au nanoparticles were loaded and used to modify the surface of the ITO conductive glass, resulting in the preparation of Au/NiO/TiO2/ITO electrodes. Then, single-stranded RNA (ssRNA) was immobilized as a probe on top of the electrode. The two would bind specifically when the target ssRNA concentration was added, and then, the sensing performance was analyzed using a series of characterization and PEC tests. The results demonstrated that the photocurrent signal response was correlated with the target RNA (tRNA) concentration, and the sensor showed a low limit of detection (LOD =0.015 pM) and a correlation coefficient of 0.99576 over a wide linear range of concentrations from 1 pM to 100 nM. The prepared biosensors showed good reproducibility, stability, and excellent specificity. The proposed Au/NiO/TiO2 composite can effectively measure the cold-resistant RNA levels in winter wheat, which provides a value for grain yield and cold-resistant breeding.

Radio frequency identification (RFID) is widely used in indoor lighting systems due to advantages, such as programmability, stability, and high detection accuracy. Herein, a multifrequency-coded RFID microstrip photosensor based on zinc oxide (ZnO)/silver (Ag)/copper sulfide (CuS) nanocomposites is designed; at the same time, it has the excellent photoelectric performance of ZnO and CuS, which enhances the response of the sensor to the light signal, and the high photoconductivity of Ag, enhances the RFID radio frequency signal, improves the reading distance and accuracy, and can be used to detect the light of four frequencies. A complementary open-loop resonator (CSRR) patch microstrip antenna was designed using high-frequency structure simulator (HFSS) software, and the structure of the photosensor was optimized. Three coding rings are designed by adjusting the length and width of the patch, so that the sensor can realize three-digit coding, and the actual antenna is prepared by sculpting technology. The nanorod-like ZnO, nanolinear Ag, and spherical CuS are prepared by a hydrothermal method, and their structures and morphologies are characterized by SEM, energy-dispersive X-ray spectrometry (EDS), XRD, TEM, and XPS. The amplitude of the antenna under the code “111” is −26.49 dB, and the detection performance is the best. The sensor made by drip coating can detect ambient light in the range of 2.833–2.928 GHz. For a light intensity of 0–53.9 klx, the response time of the photosensor is 17 s, the recovery time is 15 s, the response time of the resistance is 16 s, and the recovery time is 11 s, indicating that the ZnO/Ag/CuS nanocomposites have good responsiveness and recovery.