The facile designs and fabrication of noble metal-free electrocatalysts are highly required to achieve multifunctional catalytic activity with excellent stability in Zn-air batteries, fuel cells and water splitting systems. Herein, a heterostructure engineering is applied to construct the high performance Co, N-containing carbon-based multifunctional electrocatalysts with the feature of isotype (i.e. n-n type Co₂N_0.67-BHPC) and anisotype (i.e. p-n type Co₂O₃-BHPC) heterojunctions for ORR, OER and HER. The n-n type Co₂N_0.67-BHPC, in which biomass (e.g. mushroom)-derived hierarchical porous carbon (BHPC) incorporated with nonstoichiometric active species Co₂N_0.67, is fabricated by using an in situ protective strategy of macrocyclic central Co-N₄ from CoTPP (5,10,15,20-tetrakis(phenyl) porphyrinato cobalt) precursor through the intermolecular π-π interactions between CoTPP and its metal-free analogue H₂TPP. Meanwhile, an unprotected strategy of macrocyclic central Co-N₄ from CoTPP can afford the anisotype Co₂O₃-BHPC p-n heterojunction. The as-prepared n-n type Co₂N_0.67-BHPC heterojunction exhibited a higher density of Co-based active sites with outstanding stability and more efficient charge transfer at the isotype heterojunction interface in comparison with p-n type Co₂O₃-BHPC heterojunction. Consequently, for ORR, Co₂N_0.67-BHPC exhibits the more positive onset and half-wave potentials of 0.93 and 0.86 V vs. RHE, respectively, superior to those of the commercial 20 wt% Pt/C and most of Co-based catalysts reported so far. To drive a current density of 10 mA cm⁻², Co₂N_0.67-BHPC also shows the lower overpotentials of 0.34 and 0.21 V vs. RHE for OER and HER, respectively. Furthermore, the Zn-air battery equipped with Co₂N_0.67-BHPC displays higher maximum power density (109 mW cm⁻²) and charge–discharge cycle stability. Interestingly, the anisotype heterojunction Co₂O₃-BHPC as trifunctional electrocatalyst reveals evidently photoelectrochemical enhancement compared with the photostable Co₂N_0.67-BHPC. That is to say, isotype heterojunction material (n-n type Co₂N_0.67-BHPC) is equipped with better electrocatalytic performance than anisotype one (p-n type Co₂O₃-BHPC), but the opposite is true in photoelectrochemical catalysis. Meanwhile, the possible mechanism is proposed based on the energy band structures of the Co₂N_0.67-BHPC and Co₂O₃-BHPC and the cocatalyst effects. The present work provides much more possibilities to tune the electrocatalytic and photoelectrochemical properties of catalysts through a facile combination of heterostructure engineering protocol and macrocyclic central metal protective strategy.

在锌-空气电池，燃料电池和水分解系统中，为实现多功能催化活性以及出色的稳定性，非常需要易于设计和制造的无贵金属电催化剂。本文采用异质结构工程技术，构建了具有同型（即nn型Co ₂ N _0.67 -BHPC）和同型（即p - n型Co ₂ O ₃）特征的高性能Co，含碳碳基多功能电催化剂。-BHPC）ORR，OER和HER的异质结。所述ñ - ñ型Co ₂ Ñ _0.67 -BHPC，其中生物质（例如蘑菇）衍生的非化学计量与活性物种引入的CO分级多孔碳（BHPC）₂ Ñ _0.67，制造通过使用原位的大环中央CO-N的保护策略₄从的CoTPP（5,10,15,20-四（通过CoTPP及其不含金属的类似物H ₂ TPP之间的分子间π-π相互作用，生成苯基）卟啉前体钴。同时，CoTPP的大环中心Co-N ₄的未保护策略可以提供同型Co ₂ O ₃ -BHPC p - n异质结。准备好的n - n与p - n型Co ₂ O ₃ -BHPC异质结相比，Co ₂ N _0.67 -BHPC型异质结在同型异质结界面处表现出更高的Co基活性位点密度，具有出色的稳定性和更有效的电荷转移。因此，对于ORR，Co ₂ N _0.67 -BHPC相对于RHE分别显示出0.93 V和0.86 V的正正开始电势和半波电势，优于商用20 wt％Pt / C和大多数基于Co的Pt / C。迄今为止报道的催化剂。为了驱动10 mA cm ^-2的电流密度，Co ₂ N _0.67-BHPC还显示出相对于RER的OER和HER较低的过电势分别为0.34和0.21V。此外，配备Co ₂ N _0.67 -BHPC的锌空气电池显示出更高的最大功率密度（109 mW cm ^-2）和充放电循环稳定性。有趣的是，与光稳定的Co ₂ N _0.67 -BHPC相比，作为三官能电催化剂的异型异质结Co ₂ O ₃ -BHPC具有明显的光电化学增强作用。也就是说，同型异质结材料（nn型Co ₂ N _0.67 -BHPC）具有比同型异质结材料（p - n型Co ₂ O ₃ -BHPC），但在光电化学催化中则相反。同时，基于Co ₂ N _0.67 -BHPC和Co ₂ O ₃ -BHPC的能带结构以及助催化剂作用，提出了可能的机理。通过异质结构工程规程和大环中心金属保护策略的简便组合，本工作为调节催化剂的电催化和光电化学性质提供了更多可能性。