Photoluminescent C-dots made by a one-step electrolysis method make a selective fluorescent sensor for Al³⁺ over other metal ions.

Herein, we successfully fabricated an Al-doped α-Ga₂O₃ nanorod array on FTO using the hydrothermal and post-annealing processes. To the best of our knowledge, it is the first time that an Al-doped α-Ga₂O₃ nanorod array on FTO has been realized via a much simpler and cheaper way than that based on metal–organic chemical vapor deposition, magnetron sputtering, molecular beam epitaxy, and pulsed laser deposition. And, a self-powered Al-doped α-Ga₂O₃ nanorod array/FTO photodetector was also realized as a photoanode at 0 V (vs. Ag/AgCl) in a photoelectrochemical (PEC) cell, showing a peak responsivity of 1.46 mA/W at 260 nm. The response speed of the Al-doped device was 0.421 s for rise time, and 0.139 s for decay time under solar-blind UV (260 nm) illumination. Compared with the undoped device, the responsivity of the Al-doped device was ~5.84 times larger, and the response speed was relatively faster. When increasing the biases from 0 V to 1 V, the responsivity, quantum efficiency, and detectivity of the Al-doped device were enhanced from 1.46 mA/W to 2.02 mA/W, from ~0.7% to ~0.96%, and from ~6 × 10⁹ Jones to ~1 × 10¹⁰ Jones, respectively, due to the enlarged depletion region. Therefore, Al doping may provide a route to enhance the self-powered photodetection performance of α-Ga₂O₃ nanorod arrays.

In this study, a facile and effective route for the preparation of silver nanoparticles supported surface mesoporous silica microspheres with perpendicularly aligned mesopore channels and their antibacterial activities were reported. The surface mesoporous silica microspheres (mSiO₂) were synthesized by a sol–gel method. The mSiO₂ were then functionalized with 3-aminopropyltriethoxysilane (APTS) to provide amino functional groups for the absorption of Ag⁺. Silver nanoparticles were directly created on the surface of mSiO₂ by in situ chemical reduction of the Ag precursor using an ultrasonic wave reaction method. The prepared silver nanoparticle supported surface mesoporous silica nanocomposites (mSiO₂@NH₂@Ag) were characterized with FT-IR, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. Antibacterial activities of the synthesized mSiO₂@NH₂@Ag were investigated against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (SAU) using the conventional plate-count method. The results demonstrated that the synthesized nanocomposites exhibited excellent antibacterial properties against E. coli and SAU. Furthermore, because of the slow release property of silver, the synthesized nanocomposites can be used as an economic recyclable material in various antibacterial applications, such as water purification systems and environmental control of bacteria.

Wet-chemistry synthesis of two-dimensional Pt- and Pd-based intermetallic electrocatalysts for a wide range of applications in fuel cells.

The low quantum yields (QY) of carbon quantum dots (CQDs) not only limit their sensitivity as sensors, but also hinder their application in fluorescent anti-counterfeiting materials. To develop highly fluorescent CQDs, several factors, like a large conjugated double bond system, a rigid plane structure and electron-donating substituent group incorporation on the aromatic ring need to be considered. With this in mind, herein, highly fluorescent nitrogen-doped CQDs (N-CQDs) were successfully fabricated by a solvothermal method using ammonia, citric acid and phloroglucinol as precursors. The sensing platform based on the obtained N-CQDs was constructed to determine Fe³⁺ and ascorbic acid (AA) via the “on–off–on” fluorescence principle. The fluorescence of the N-CQDs was effectively quenched upon addition of Fe³⁺, and then, restored by AA. The detection limits for Fe³⁺ and AA were determined to be 0.28 μM and 0.81 μM within the respective ranges of 1–10 μM and 30–90 μM. It is worth noting that the proposed strategy was successfully applied to monitor AA in fruit samples with satisfactory results. In addition, we successfully applied N-CQDs to information anti-counterfeiting and molecular logic gate operations, which confirmed their great potential application prospects.