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The control of charge transfer between radical anions and cations is a promising way for decoding the emission mechanism in electrochemiluminescence (ECL) systems. Herein, a type of donor-acceptor (D-A) covalent organic framework (COF) with triphenylamine and triazine units is designed as a highly efficient ECL emitter with tunable intrareticular charge transfer (IRCT). The D-A COF demonstrates 123 folds enhancement in ECL intensity compared with its benzene-based COF with small D-A contrast. Further, the COF’s crystallinity- and protonation-modulated ECL behaviors confirm ECL dependence on intrareticular charge transfer between donor and acceptor units, which is rationalized by density functional theory. Significantly, dual-peaked ECL patterns of COFs are achieved through an IRCT mediated competitive oxidation mechanism: the coreactant-mediated oxidation at lower potential and the direct oxidation at higher potential. This work provides a new fundamental and approach to improve the ECL efficiency for designing next-generation ECL devices.

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Summary Memristive devices share remarkable similarities to biological synapses, dendrites, and neurons at both the physical mechanism level and unit functionality level, making the memristive approach to neuromorphic computing a promising technology for future artificial intelligence. However, these similarities do not directly transfer to the success of efficient computation without device and algorithm co-designs and optimizations. Contemporary deep learning algorithms demand the memristive artificial synapses to ideally possess analog weighting and linear weight-update behavior, requiring substantial device-level and circuit-level optimization. Such co-design and optimization have been the main focus of memristive neuromorphic engineering, which often abandons the “non-ideal” behaviors of memristive devices, although many of them resemble what have been observed in biological components. Novel brain-inspired algorithms are being proposed to utilize such behaviors as unique features to further enhance the efficiency and intelligence of neuromorphic computing, which calls for collaborations among electrical engineers, computing scientists, and neuroscientists.

Photoreduction of CO 2 to CH 4 , which is an 8-electron photoelectrochemical process, represents one of the most appealing approaches that tackles the global warming challenge and fuel crisis. To achieve this, highly efficient and selective catalysts are desired. In this work, we successfully developed a metal-free 2D/2D heterostructured catalyst for photoreduction of CO 2 to CH 4 with black phosphorus (BP) and covalent triazine framework (CTF). The synthesized CTF-BP heterostructure catalyst was well characterized using the high-resolution TEM (HRTEM), AFM, XPS and Raman. Compared with the pristine BP or CTF, the photoreduction of CO 2 to CO rate over the CTF-BP catalyst (4.60 μmol g −1 h −1 ) is 3 and 2 times higher than those over BP and CTF catalysts, respectively. The photoreduction of CO 2 to CH 4 rate over the CTF-BP catalyst (7.81 μmol g −1 h −1 ) is 23 times and 16 times higher than those over BP and CTF catalysts, respectively. This indicates that the CTF-BP heterostructure dramatically enhances the photocatalytic selectivity for CO 2 to CH 4 over CO. The present work not only develops a metal-free highly efficient and selective catalyst for photoreduction of CO 2 but also provides a new heterostructure engineering route for designing and synthesizing highly active and metal-free catalysts applied in sustainable solar-to-chemical energy conversion and environmental remediation.

Metal organic gels (MOGs) have emerged as a new class of smart soft materials with superb luminescence properties and have attracted tremendous attention in various aspects. However, the electrochemiluminescence (ECL) behavior of MOGs has not been reported yet. In this work, cathode electrochemiluminescence (ECL) emission of terbium(III) organic gels (TOGs) was reported for the first time with potassium persulfate (KSO) as an efficient coreactant. TOGs were synthesized by a facile one-step strategy, mixing terbium ions (Tb) and the ligand 4'-(4-carboxyphenyl)-2,2':6',2''-terpyridine (Hcptpy) at room temperature. The possible strong green ECL emission mechanism was discussed in detail and ascribed to the external coreactant enhancement and internal antenna effect enhancement. Moreover, the promising application of TOGs in analytical chemistry was clarified by the ECL on-off detection of tetracycline. This remarkable discovery of ECL emission of TOGs may pioneer the application of MOGs in ECL fields.

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