Novel Ti3C2/polyacrylamide nanocomposite hydrogels with excellent mechanical and drug release performances were fabricated via in situ polymerization, employing ultralow content Ti3C2 nanosheets as crosslinkers instead of organic crosslinkers.

Optimized surface facet of the catalysts is an efficient strategy to boost catalytic purification of diesel soot as important components of atmospheric fine particles. Herein, we have elaborately constructed the nanocatalysts of Au nanoparticles supported on the well-defined CeO 2 (rod, cube, and polyhedron) with predominantly exposed facets of {110}, {100}, and {111}, respectively. The strong interaction between Au and CeO 2 with the optimal crystal facet is crucial to adjust the active site density for activated O 2 , and the synergy effect of Au and the CeO 2 {110} facet possesses the largest density of active sites compared with other crystal facets of {100} and {111}. The catalytic activity for soot combustion was tuned by exposed crystal facets of CeO 2 . The Au/CeO 2 -rod catalyst exhibits the highest catalytic activity (T 50 = 350 °C, TOF = 0.18 h −1 ) and the lowest apparent activation energy (72 kJ mol −1 ) during soot combustion. Based on the results of in situ Raman spectra, the formation and stability of oxygen vacancy located at the interface of the Au−O−Ce bond, boosting the key step of NO oxidation to NO 2 , are dependent on the exposed crystal facets of CeO 2 . It highlights a new strategy for the fabrication of high-efficient CeO 2 -based catalysts for the removal of soot particles or other pollution.

The modulation effect manifests an encouraging potential to enhance the performance of single‐atom catalysts; however, the in‐depth study about this effect for the isolated diatomic sites (DASs) remains a great challenge. Herein, a proximity electronic effect (PEE) of Ni/Co DASs is proposed that is anchored in N‐doped carbon (N‐C) substrate (NiCo DASs/N‐C) for synergistic promoting electrocatalytic oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). Benefiting from the PEE of adjacent Ni anchored by four nitrogen (Ni‐N4) moiety, NiCo DASs/N‐C catalyst exhibits superior ORR and HER activity. In situ characterization results suggest Co anchored by four nitrogen (Co‐N4) as main active site for O2 adsorption‐activation process, which promotes the formation of key *OOH and the desorption of *OH intermediate to accelerate the multielectron reaction kinetics. Theoretical calculation reveals the adjacent Ni‐N4 site as a modulator can effectively adjust the electronic localization of proximity Co‐N4 site, promoting the *OH desorption and *H adsorption on Co‐N4 site, thereby boosting ORR and HER process significantly. This study opens a new opportunity for rationally regulating the electronic localization of catalytic active centers by proximity single‐atom moiety, as well as provides guidance for designing high‐efficiency bifunctional electrocatalysts for promising applications.

We have designed and elaborately fabricated the ordered hierarchical macro-meso-microporous catalysts of Ce0.25Zr0.75O2-supported Pt-embedded KMnO x nanoparticles (OMMM Pt-KMnO x /Ce0.25Zr0.75O2). Three dimensionally ordered macro-mesoporous (3DOMM) Ce0.25Zr0.75O2 oxide was synthesized by the combined methods of evaporation-induced interfacial self-assembly (EISA) and colloidal crystal templates (CCT). KMnO x nanoparticles (NPs) possess the natural microporous nanostructure of an octahedral molecular sieve (OMS) with an average size of 0.46 nm. Pt nanoclusters were anchored in situ at the microporous structure of KMnO x NPs and formed Pt-KMnO x active sites. For the OMMM Pt-KMnO x /Ce0.25Zr0.75O2 catalyst, a 3D ordered macroporous (250 nm) structure can enhance contact efficiency between soot and catalysts, and a high specific surface area with contributions from ordered mesopores (5 nm) is beneficial for dispersion of KMnO x NPs and activation of gaseous reactants (O2 and NO). Meanwhile, a microporous (0.46 nm) structure can anchor K sites and ultrafine Pt nanoclusters. The synergetic effect of ternary K-Mn-Pt components can transform gas reactants to the effective intermediate species and thereafter oxidize the well-dispersed soot particles. The OMMM Pt-KMnO x /Ce0.25Zr0.75O2 catalyst possesses high catalytic activity and stability for soot oxidation under the conditions of loose contact: i.e., its TOF value is 2.10 h–1 at 290 °C, which is more than a 4-fold increase over the 3DOMM Ce0.25Zr0.75O2 support (0.47 h–1). The architected hierarchical porous structure rationalizes an alternative protocol to improve solid–solid contact and the resulting activity, which can be further applied to other catalysis systems with different catalysts and reactants.