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.

High activity, high stability, and low cost have always been the pursuit of photocatalyst design and development. Herein, a simple method is used to integrate abundant anion vacancies (VS) and cation vacancies (VZn) on the surface of ZnS (M–ZnS), deriving VS and VZn pairs (vacancy pairs), isolated Zn atoms (Zniso), and isolated S atoms (Siso). Abundant surface vacancy defects fully expose and activate the surface atoms, regulate the band structure, and significantly improve the separation of photogenerated carriers. M–ZnS is endowed with high activity, and the average hydrogen production rate of the optimal sample increases to 576.07 μmol·g–1·h–1 (λ > 400 nm). Theoretical simulations indicate that the activated Zn atoms are the dominant active sites via the formation of a Zn–OH bond with H2O. Especially, the strong interactions of electrons in atomic orbitals at vacancy pairs and the introduction of VZn are conducive to high stability. The optimal sample maintains an average hydrogen production rate of 6.59 mmol·g–1·h–1 (300 W Xe lamp) after nine cycles. Hence, this work deepens the understanding of vacancy defects and provides an idea for the design of a stable photocatalyst.

For developing highly sensitive, selective and stable gas sensing materials for the detection of volatile organic compounds, we report porous micro/nano-level structured Ag-LaFeO3 nanoparticles which have been successfully synthesized using a lotus leaf as a bio-template via a sol–gel process.

Silver-doped LaFeO molecularly imprinted polymers (SLMIPs) were synthesized by a sol-gel method combined with molecularly imprinted technology as precursors. The precursors were then used to prepare SLMIPs cage (SLM-cage) and SLMIPs core-shell (SLM-core-shell) structures by using a carbon sphere as the template and hydrothermal synthesis, respectively. The structures, morphologies, and surface areas of these materials were determined, as well as their gas-sensing properties and related mechanisms. The SLM-cage and SLM-core-shell samples exhibited good responses to methanol gas, with excellent selectivity. The response and optimum working temperature were 16.98 °C and 215 °C, 33.7 °C and 195 °C, respectively, with corresponding response and recovery times of 45 and 50 s (SLM-cage) and 42 and 57 s (SLM-core-shell) for 5 ppm methanol gas. Notably, the SLM-cage and SLM-core-shell samples exhibited lower responses (≤5 and ≤7, respectively) to other gases, including ethanol, ammonia, benzene, acetone, and toluene. Thus, these materials show potential as practical methanol detectors.

Here we report a mesoporous TiO2 with large specific surface area and rich oxygen vacancies using Ti-based MOF (MIL-125) as precursor through high-temperature annealing. Such integration of unique mesoporous structure...

In this work, TiO2 photocatalysts, co-doped with transition metal ions vanadium (V) and cobalt (Co) ((V,Co)–TiO2), were synthesized by the sol–gel method. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption and desorption measurement, UV-Vis absorption and photoluminescence spectrum (PL) spectra. The results show that V and Co co-doping has significant effects on sample average crystalline grain size, absorption spectrum, recombination efficiency of photo-induced electron-hole pairs (EHPs), and photocatalytic degradation efficiency of methylene blue (MB). (V,Co)–TiO2 photocatalyst exhibits an obvious red shift of the absorption edge to 475 nm. Photocatalytic degradation rate of (V,Co)–TiO2 sample for MB in 60 min is 92.12% under a Xe lamp with a cut-off filter (λ > 400 nm), which is significantly higher than 56.55% of P25 under the same conditions. The first principles calculation results show that V and Co ions doping introduces several impurity energy levels, which can modulate the location of the valence band and conduction band. An obvious lattice distortion is produced in the meantime, resulting in the decrease in photo-generated EHP recombination. Thus, (V,Co)–TiO2 photocatalyst performance is significantly improved.

Applying metal–organic framework (MOF) materials to perovskite solar cells (PSCs) is an innovative and promising direction in the current photovoltaic field, especially in low‐cost carbon‐based PSCs without hole transport layer. Herein, a novel mesoporous anatase TiO2 nanocrystalline with pie morphology, large specific surface area (SSA), and outstanding wettability is successfully prepared by sintering the NH2‐MIL‐125 at 500 °C for 6 h. The TiO2 derived from NH2‐MIL‐125 possesses excellent penetration and crystallinity of perovskite in the electron transporting layer (ETL), and exhibits appropriate work function which matches relatively better with the conduction band of perovskite. Meanwhile, the power conversion efficiencies (PCEs) of the two PSC devices based on the as‐prepared TiO2 are 13.49% and 12.55%, respectively. Moreover, both of these devices exhibit good stability.

An ultrasensitive methanol gas sensing device based on the quasi-molecular imprinting technology (quasi-MIT) is studied in this work. We applied the sol-gel method (ALS denotes Ag-LaFeO3 prepared by the sol-gel method) and combustion synthesis (ALC denotes Ag-LaFeO3 prepared by combustion synthesis) to prepare Ag-LaFeO3 based sensors. The morphologies and structures of the Ag-LaFeO3 materials were examined via various detection techniques. The ALSM and ALCM sensor (ALSM and ALCM denotes the devices prepared by coating the ALS and ALC materials with methanol, respectively) fabricated using the sol-gel method and combustion synthesis combined with quasi-MIT exhibit good gas sensing properties to methanol, in contrast with the two devices (ALSW and ALCW denote the devices prepared for coating the ALS and ALC materials with water, respectively) without the use of quasi-MIT. The results show that quasi-MIT introduced the target gas in the fabrication process of the device, playing an important role in the design of the ultrasensitive methanol gas sensor. The sensing response and the optimum working temperature of ALSM and ALCM gas sensor are 52.29 and 155 °C and 34.89 and 155 °C, respectively, for 5 ppm methanol, and the highest response to other gases is 8. The ALSM and ALCM gas sensors reveal good selectivity and response for methanol.