Single metal atom photocatalysts have received widespread attention due to the rational use of metal resources and maximum atom utilization efficiency. In particular, N-rich amorphous g-C 3 N 4 is always used as a support to anchor single metal atoms. However, the enhancement of photocatalytic activity of g-C 3 N 4 by introducing a single atom is limited due to the bulk morphology and the excess defects of amorphous g-C 3 N 4 . Here, we report crystalline g-C 3 N 4 nanorod supported copper single atoms by molten salts and the reflux method. The prepared single Cu atoms/crystalline g-C 3 N 4 photocatalyst (Cu-CCN) shows highly selective and efficient photocatalytic reduction of CO 2 under the absence of any cocatalyst or sacrificial agent. The introduction of single Cu atoms can be used as the CO 2 adsorption site, thus increasing the adsorption capacity of Cu-CCN samples to CO 2 . Theoretical calculation results show that reducing CO 2 to CH 4 on Cu-CCN samples is an entropy-increasing process, whereas reducing CO 2 to CO is an entropy-decreasing process. As a result, the Cu-CCN samples exhibited enhanced photocatalytic CO 2 reduction with nearly 100% selective photocatalytic CO 2 to CO conversion. The mechanism of photocatalytic CO 2 reduction over Cu-CCN samples was proposed based on in situ Fourier transform infrared spectra, X-ray absorption spectroscopy, and density functional theory calculation. This work provides an indepth understanding of the design of photocatalysts for enhancing active sites of the reactants.

NMDA-type glutamate receptors (NMDARs) are currently regarded as paramount in the potent and selective disruption of synaptic plasticity by Alzheimer’s disease amyloid β-protein (Aβ). Non-NMDAR mechanisms remain relatively unexplored. Here we describe how Aβ facilitates NMDAR-independent long-term depression of synaptic transmission in the hippocampus in vivo. Synthetic Aβ and Aβ in soluble extracts of Alzheimer’s disease brain usurp endogenous acetylcholine muscarinic receptor-dependent long-term depression, to enable long-term depression that required metabotropic glutamate-5 receptors (mGlu5Rs). We also find that mGlu5Rs are essential for Aβ-mediated inhibition of NMDAR-dependent long-term potentiation in vivo. Blocking Aβ binding to cellular prion protein with antibodies prevents the facilitation of long-term depression. Our findings uncover an overarching role for Aβ-PrPC-mGlu5R interplay in mediating both LTD facilitation and LTP inhibition, encompassing NMDAR-mediated processes that were previously considered primary.

Single‐atom photocatalysis has been demonstrated as a novel strategy to promote heterogeneous reactions. There is a diversity of monoatomic metal species with specific functions; however, integrating representative merits into dual‐single‐atoms and regulating cooperative photocatalysis remain a pressing challenge. For dual‐single‐atom catalysts, enhanced photocatalytic activity would be realized through integrating bifunctional properties and tuning the synergistic effect. Herein, dual‐single‐atoms supported on conjugated porous carbon nitride polymer are developed for effective photocatalytic CO2 reduction, featuring the function of cobalt (Co) and ruthenium (Ru). A series of in situ characterizations and theoretical calculations are conducted for quantitative analysis of structure–performance correlation. It is concluded that the active Co sites facilitate dynamic charge transfer, while the Ru sites promote selective CO2 surface‐bound interaction during CO2 photoreduction. The combination of atom‐specific traits and the synergy between Co and Ru lead to the high photocatalytic CO2 conversion with corresponding apparent quantum efficiency (AQE) of 2.8% at 385 nm, along with a high turnover number (TON) of more than 200 without addition of any sacrificial agent. This work presents an example of identifying the roles of different single‐atom metals and regulating the synergy, where the two metals with unique properties collaborate to further boost the photocatalytic performance.

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