Pursuing and developing effective methodologies to construct highly active catalytic sites to maximize the atomic and energy efficiency by material engineering are attractive. Relative to the tremendous researches of carbon-based single atom systems, the construction of bio-applicable single atom materials is still in its infancy. Herein, we propose a facile and general interfacial-confined coordination strategy to construct high-quality single-atom nanotherapeutic agent with Fe single atoms being anchored on defective carbon dots confined in a biocompatible mesoporous silica nanoreactor. Furthermore, the efficient energy conversion capability of silica-based Fe single atoms system has been demonstrated on the basis of the exogenous physical photo irradiation and endogenous biochemical reactive oxygen species stimulus in the confined mesoporous network. More importantly, the highest photothermal conversion efficiency with the mechanism of increased electron density and narrow bandgap of this single atom structure in defective carbon was proposed by the theoretical DFT calculations. The present methodology provides a scientific paradigm to design and develop versatile single atom nanotherapeutics with adjustable metal components and tune the corresponding reactions for safe and efficient tumor therapeutic strategy.

We show experimentally the phenomenon of internal signal stochastic resonance in the Belousov-Zhabotinsky reaction without external signal. The chemical reaction is placed in an excitable state near a Hopf bifurcation in a CSTR. When the flow rate is perturbed by stochastic noise, noise-induced oscillations are observed, and two closely spaced, large-amplitude spikes appear nearly periodically at the proper noise level. More importantly, analysis from the power spectra and interspike interval histogram of the time series output, the coherence of these noise-induced oscillations, is maximal at an optimal noise intensity, indicating the occurrence of internal signal stochastic resonance.

We have developed a Keggin polyoxometalate (POM)‐based ionic‐liquid (IL)‐immobilizing rhodium single‐atom Rh catalyst (MTOA)5[SiW11O39Rh] (MOTA=methyltrioctylammonium cation) that can afford exceptionally high catalytic activity for the hydroformylation of alkenes to produce aldehydes at an ultralow loading of Rh (ca. 3 ppm). For styrene hydroformylation, both the conversion and the yield of the aldehyde can reach almost 99 %, and a TOF as high as 9000 h−1 was obtained without using any phosphine ligand in the reaction process. Further characterization by FTIR, ICP and ESI‐MS analysis revealed that the single Rh atom was incorporated in the lacunary POM anions. In particular, the bulky IL cation can play an additional role in stabilizing Rh species and thus prevent aggregation and leaching of Rh species. The IL catalyst was miscible with n‐hexane at temperatures; this contributed to exceptionally high activity for hydroformylation even at ultra‐low loading of IL catalyst.

Oxidative desulfurization is a highly effective approach to decrease the sulfur content in transportation fuel and has become an attractive research topic in recent years. Herewith, we have developed a new kind of carboxylic acid-functionalized imidazolium-based ionic liquid-stabilized Ti oxoclusters via a solvothermal method. The as-synthesized Ti oxoclusters were investigated by elemental analysis, Fourier transform infrared spectroscopy, diffuse reflectance UV–vis, X-ray diffraction, thermogravimetric analysis, high-resolution transmission electron microscopy (HRTEM), and high-angle annular dark field–scanning TEM. Characterization indicated that Ti oxoclusters existed in the form of subnanosized structure and uniformly dispersed with an average particle size of ca. 1 nm due to the protection role of the ionic liquids (ILs). Especially, Ti oxo–HSO4 afforded a superior catalytic activity in the extraction and catalytic oxidative desulfurization process with MeOH as an extractant and H2O2 as an oxidant. The full removal of dibenzothiophene in model fuels was achieved within 30 min at 60 °C. Besides, the Ti oxoclusters were robust and exhibited high stability in consecutive catalytic recycles. The parent Ti oxoclusters treated with H2O2 can afford Ti–OOH species, which was catalytically active species. The anion HSO4 – in IL played a crucial role in the activation of Ti–hydroperoxo species by forming hydrogen bonds. This may provide a new insight into the construction of metal oxoclusters for oxidative desulfurization.

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