We performed a co-condensation reaction between aromatic aldehyde and aromatic diamine monomers on a highly oriented pyrolytic graphite surface either at a solid/liquid interface at room temperature or in low vacuum with moderate heating. With this simple and moderate methodology, we have obtained surface-confined 2D covalent organic frameworks (COFs) with few defects and almost entire surface coverage. The single crystalline domain can extend to more than 1 μm(2). By varying the backbone length of aromatic diamines the pore size of 2D surface COFs is tunable from ∼1.7 to 3.5 nm. In addition, the nature of the surface COF can be modified by introducing functional groups into the aromatic amine precursor, which has been demonstrated by introducing methyl groups to the backbone of the diamine. Formation of small portions of bilayers was observed by both scanning tunneling microscopy (STM) and AFM, which clearly reveals an eclipsed stacking manner.

Though moderate heating in a controlled environment is generally considered to be necessary, in this work we show that the most important prerequisite for obtaining high quality 2D imine polymers at the interface is the concentration and molar ratio of building blocks on the surface. With diverse monomers we have demonstrated that the concentration-in-control strategy is a general and powerful way to construct covalent single layer 2D imine polymers with high regularity at the solid/liquid interface.

Aqueous zinc‐ion batteries (AZIBs) have attracted increasing attention as a next‐generation energy storage system because of their inherent safety, high capacity, and cost effectiveness. However, the poor cycling durability and low coulombic efficiency of zinc anodes substantially restrict their further development, which should be attributed to the severe dendrite growth, shape change, surface passivation, self‐corrosion, and byproduct formation across the repeated plating/stripping processes. To address these critical issues, great efforts have been dedicated to the rational design of zinc anodes. In this review, different strategies for the performance improvement of zinc anodes are summarized as well as recent research that boosts their development. These methods include the surface modification, novel host‐anode development for zinc, electrolyte formulation, and separator design. Their respective advantages and defects are compared and discussed in detail. The challenges and further prospects in this field are also addressed. This work is designed to shed light on advanced zinc anode constructions for high‐performance AZIBs assembly.