2D materials exhibit superior properties in electronic and optoelectronic fields. The wide demand for high‐performance optoelectronic devices promotes the exploration of diversified 2D materials. Recently, 2D covalent organic frameworks (COFs) have emerged as next‐generation layered materials with predesigned π‐electronic skeletons and highly ordered topological structures, which are promising for tailoring their optoelectronic properties. However, COFs are usually produced as solid powders due to anisotropic growth, making them unreliable to integrate into devices. Here, by selecting tetraphenylethylene monomers with photoelectric activity, elaborately designed photosensitive 2D‐COFs with highly ordered donor‐acceptor topologies are in situ synthesized on graphene, ultimately forming COF‐graphene heterostructures. Ultrasensitive photodetectors are successfully fabricated with the COFETBC–TAPT‐graphene heterostructure and exhibited an excellent overall performance with a photoresponsivity of ≈3.2 × 107 A W−1 at 473 nm and a time response of ≈1.14 ms. Moreover, due to the high surface area and the polarity selectivity of COFs, the photosensing properties of the photodetectors can be reversibly regulated by specific target molecules. The research provides new strategies for building advanced functional devices with programmable material structures and diversified regulation methods, paving the way for a generation of high‐performance applications in optoelectronics and many other fields.

In article number 1907242, Kai Xi, Peng Zhan, Fei Xu, Yanqing Lu, and co‐workers report an ultrasensitive photodetector using 2D covalent organic framework (COF)–graphene heterostructures. By selecting photoactive monomers, elaborately designed photosensitive 2D‐COFs with highly ordered donor–acceptor topologies are in situ synthesized on graphene, ultimately forming COF–graphene heterostructures. This study provides new strategies for building advanced functional devices with programmable material structures and diversified regulation methods.

Ethylene glycol is regarded as a promising C2 platform molecule due to the fast development of its production from sustainable biomass. This study inquired the structural requirements of Co-based catalysts for the liquid-phase ammonolysis of ethylene glycol to value-added ethanolamine. We showed that the rate and selectivity of ethylene glycol ammonolysis on γ-Al2O3-supported Co catalysts were strongly affected by the metal particle size within the range of 2–10 nm, among which Co nanoparticles of ~4 nm exhibited both the highest ethanolamine selectivity and the highest ammonolysis rate based on the total Co content. Doping of a moderate amount of Ag further promoted the catalytic activity without affecting the selectivity. Combined kinetic and infrared spectroscopic assessments unveiled that the addition of Ag significantly destabilized the adsorbed NH3 on the Co surface, which would otherwise be strongly bound to the active sites and inhibit the rate-determining dehydrogenation step of ethylene glycol.