Single-atom catalysts anchoring offers a desirable pathway for efficiency maximization and cost-saving for photocatalytic hydrogen evolution. However, the single-atoms loading amount is always within 0.5% in most of the reported due to the agglomeration at higher loading concentrations. In this work, the highly dispersed and large loading amount (>1 wt%) of copper single-atoms were achieved on TiO₂, exhibiting the H₂ evolution rate of 101.7 mmol g⁻¹ h⁻¹ under simulated solar light irradiation, which is higher than other photocatalysts reported, in addition to the excellent stability as proved after storing 380 days. More importantly, it exhibits an apparent quantum efficiency of 56% at 365 nm, a significant breakthrough in this field. The highly dispersed and large amount of Cu single-atoms incorporation on TiO₂ enables the efficient electron transfer via Cu²⁺-Cu⁺ process. The present approach paves the way to design advanced materials for remarkable photocatalytic activity and durability.

Traditional sensor materials for detecting gaseous and volatile compounds still have relatively low sensitivity and high price, which limits their large-scale applications. It is critical to improve the changes of sensor resistance vs. the amount of adsorbed target gas by promoting the designed surface reaction. Herein, an atomically deposited Ag on tungsten oxide nanoplate (AD-Ag-WO₃) sensor is synthesized by a low temperature deposition method to tackle the existing problems. It is found that the AD-Ag-WO₃ is very sensitive when exposed to triethylamine (TEA). Meanwhile, the films showed an unexpectedly high response and low operating temperature due to the deposition of the single-atom silver. Among all of the synthesized materials, 0.01 M AD-Ag-WO₃ sensors exhibited far superior gas sensing performance (5150 for 50 ppm at 175 °C) to TEA, which is enhanced 50 times compared with that of pure WO₃ (110 for 50 ppm at 250 °C). Simultaneously, the AD-Ag-WO₃ sensor also showed an extremely low limit of detection (LLD) (1.7 ppb, far superior to that of traditional materials) and an ultrahigh selectivity for TEA. Such an excellent performance can be ascribed to the presence of single-atom Ag. The synthetic method of loading metal single atoms onto gas-sensitive materials can be extended to other similar composite materials, which opens the way for the industrial application of gas-sensitive sensors induced by designed single-atoms.

COF-supported ultrafine crystalline Fe–TiO ₂ nanoparticles were prepared, which show ambient light photocatalytic activity with high efficiency, stability, and recyclability.