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[Display omitted] • Insoluble Mn 3 (PO 4) 2 coating layer is electrodeposited on the amorphous MnO 2 surface. • Long-range disordered MnO 2 can release strain and provide plenty structural defects. • Mn 3 (PO 4) 2 layer can be transferred to compact coating via electrochemical activation. • Mn 3 (PO 4) 2 can prevent the dissolution of amorphous MnO 2 to enhance the stability. • The composite reveals excellent energy storage performance as the ZIBs cathode. Manganese-based composites are considered as valid cathodes for aqueous zinc-ion batteries (ZIBs). However, the gradually dissolute and structural collapse of the Mn species are still restricting the practical application. Herein, an electrochemical activated insoluble Mn 3 (PO 4) 2 coating layer is tightly encapsulated on soluble amorphous MnO 2 nanosheets (AMO@A-MP/CC). The long-range disordered atomic arrangements of amorphous MnO 2 can release the strain due to volume changes, while the abundant structural defects can act as ion storage sites with high reversibility, thus effectively enhance the intrinsic capacity and reduce the capacity degradation. Moreover, the compact and insoluble Mn 3 (PO 4) 2 coating layer can inhibit the gradual diffusion of Mn2+ into electrolyte and enhance structural stability of amorphous MnO 2. Therefore, AMO@A-MP/CC composite delivers ultra-high specific capacity (420.0 mAh g−1 at 0.3 A g−1), remarkable cyclic stability (97.5 % capacity retention after 1000 cycles) and excellent rate capability (224.2 mAh g−1 at 3.0 A g−1). Significantly, the energy-density of 225.0 Wh kg−1 for single electrode and bendable ability can be achieved in the flexible Zn/AMO@A-MP battery, demonstrating the synergistic effect of amorphous structure and surface coating for future ZIBs development. [ABSTRACT FROM AUTHOR]

• The graphene-like g-C 3 N 4 was coated successfully on the surface of porous ZnO. • PNS-ZnO@g-CN exhibited higher photocatalytic activity for CO 2 reduction. • G-CN content has great influence on the photocatalytic performance of composites. • The loading of g-CN nanofilms can improve the chemisorption of CO 2 on the surface of ZnO. • Formation of heterojunction in composites can depress the recombination of photo-carriers. Porous ZnO nanosheets (PNS-ZnO) were prepared by calcining ZnS(en) 0.5 (en = ethylenediamine) nanosheets in air, and g-C 3 N 4 (g-CN) nanofilms were coated on the surface of PNS-ZnO by thermal deposition using bulk g-C 3 N 4 as precursor. Experimental results showed that the graphene-like g-C 3 N 4 could be deposited on the surface of ZnO to form nanocomposites with core/shell structure. After the loading of g-CN, the light absorption and chemical adsorption of CO 2 over PNS-ZnO were improved obviously and the recombination of photogenerated electron and hole was greatly depressed due to the formation of heterojunction between PNS-ZnO and g-CN. All PNS-ZnO@g-CN nanocomposites exhibited much higher photocatalytic activity for CO 2 reduction with H 2 O vapor when compared to pure PNS-ZnO and bulk g-CN. The loading amount of g-CN had significant influence on the light absorption and photocatalytic activity, and PNS-ZnO@g-CN-0.4 exhibited the best photocatalytic performance, for which H 2 , CH 4 and CO production rates of 22.7, 30.5 and 16.8 μmol/g cat /h can be obtained, respectively. [ABSTRACT FROM AUTHOR]