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Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of the stable N N triple bonds. Herein, we design a new MoS2 with in-plane defect cluster through a bottom-up approach for the first time, where the defect cluster is composed of three adjacent S vacancies. The well-defined in-plane defect clusters could contribute to the strong chemical adsorption and activation towards inert nitrogen, achieving an excellent eNRR performance with an ammonia yield rate of 43.4 ± 3 μg h−1 mgcat.−1 and a Faradaic efficiency of 16.8 ± 2% at −0.3 V (vs. RHE). The performance is much higher than that of MoS2 with the edge defect. Isotopic labeling confirms that N atoms of produced NH4+ originate from N2. Furthermore, the in-plane defect clusters realized the alternate hydrogenation of nitrogen in a side-on way to synthesize ammonia. This work provides a prospecting strategy for fine-tuning in-plane defects in a catalyst, and also promotes the progress of eNRR.

The difficulty of adsorption and activation of CO2 at the catalytic site and rapid recombination of photogenerated charge carriers severely restrict the CO2 conversion efficiency. Here, we fabricate a novel alkaline Co(OH)2-decorated ultrathin 2D titanic acid nanosheet (H2Ti6O13) catalyst, which rationally couples the structural and functional merits of ultrathin 2D supports with catalytically active Co species. Alkaline Co(OH)2 beneficially binds and activates CO2 molecules, while monolayer H2Ti6O13 acts as an electron relay that bridges a photosensitizer with Co(OH)2 catalytic sites. As such, photoexcited charges can be efficiently channeled from light absorbers to activated CO2 molecules through the ultrathin hybrid Co(OH)2/H2Ti6O13 composite, thereby producing syngas (CO/H2 mixture) from photoreduction of CO2. High evolution rates of 56.5 μmol h-1 for CO and 59.3 μmol h-1 for H2 are achieved over optimal Co(OH)2/H2Ti6O13 by visible light illumination. In addition, the CO/H2 ratio can be facilely tuned from 1:1 to 1:2.4 by changing the Co(OH)2 content, thus presenting a feasible approach to controllably synthesize different H2/CO mixtures for target applications.

Electrochemical nitrogen reduction is suffering from the bottleneck of poor activity and low electron selectivity. Herein, we precisely synthesize an efficient electrocatalyst using phosphotungstic acid as a platform to anchor Bi species on the four-fold hollow site and associate with Li species on the three-fold hollow site. The well-designed catalyst shows a significant eNRR performance with an ammonia yield rate of 61 ± 1 μg h-1 mgcat.-1 and a recorded Faradaic efficiency of 85 ± 2% at -0.1 V vs. RHE. Isotopic labeling verifies that N atoms of formed NH4+ originate from N2. In situ experiments and theoretical calculations reveal that the Biδ+ species could promote the effective activation and hydrogenation of dinitrogen molecules at the adjacently unsaturated W active sites, and the incorporated Li species reduce the hydrogen reduction rate in the undesirable water splitting. This synergistic functionalization of Bi and Li species contributes to the high-efficient catalyst.