Highly active and robust eletcrocatalysts based on earth-abundant elements are desirable to generate hydrogen and oxygen as fuels from water sustainably to replace noble metal materials. Here we report an approach to synthesize porous hybrid nanostructures combining amorphous nickel-cobalt complexes with 1T phase molybdenum disulfide (MoS2) via hydrazine-induced phase transformation for water splitting. The hybrid nanostructures exhibit overpotentials of 70 mV for hydrogen evolution and 235 mV for oxygen evolution at 10 mA cm−2 with long-term stability, which have superior kinetics for hydrogen- and oxygen-evolution with Tafel slope values of 38.1 and 45.7 mV dec−1. Moreover, we achieve 10 mA cm−2 at a low voltage of 1.44 V for 48 h in basic media for overall water splitting. We propose that such performance is likely due to the complete transformation of MoS2 to metallic 1T phase, high porosity and stabilization effect of nickel-cobalt complexes on 1T phase MoS2.

External fields are introduced to catalytic processes to improve catalytic activities. The light field effect plays an important role in electrocatalytic processes, but is not fully understood. Here we report a series of photo-coupled electrocatalysts for CO 2 reduction by mimicking the structure of chlorophyll. The porphyrin-Au catalyst exhibits a high turnover frequency of 37,069 h −1 at −1.1 V and CO Faradaic efficiency (FE) of 94.2% at −0.9 V. Under visible light, the electrocatalyst reaches similar turnover frequency and FE with potential reduced by ~ 130 mV. Interestingly, the light-induced positive shifts of 20, 100, and 130 mV for porphyrin-Co, porphyrin-Cu, and porphyrin-Au electrocatalysts are consistent with their energy gaps of 0, 1.5, and 1.7 eV, respectively, suggesting the porphyrin not only serves as a ligand but also as a photoswitch to regulate electron transfer pathway to the metal center.

Highly active and durable electrocatalysts are of great significance to accelerate the sluggish oxygen evolution and oxygen reduction reaction (OER and ORR) which are indispensable processes in practical devices such as metal–air batteries. Herein, the authors integrate morphological design with compositional manipulation, and successfully achieve well‐defined CoNiFe sulfide mesoporous nanospheres (CoNiFe‐S MNs). The as‐prepared CoNiFe‐S MNs exhibit superior OER and ORR catalytic activity, delivering a low overpotential of only 199 mV at a current density of 10 mA cm−2 in 1 m KOH solution and a half‐wave potential of 0.78 V in 0.1 m KOH solution toward OER and ORR, respectively. The CoNiFe‐S MNs involved Zn–air battery exhibits remarkable charge–discharge performance (voltage gap of 0.76 V at 2 mA cm−2) and high power density (over 140 mW cm−3). Extended‐time durability tests validate the structural recoverability of the mesoporous morphology, and the remarkable performance can be attributed to the intrinsic synergistic effect of heterometallic ions. It is believed that the method could pave the way for the design of novel electrocatalysts for Zn–air batteries.

world-record SVG rate under 1 sun was 4.0 kg m −2 h −1 , which was achieved in a hydrophilic hydrogel evaporator with hydrophobic island-shaped patches. [25] Unfortunately, affected by seasons or regions, the outdoor sunlight intensity is usually far lower than 1 sun, [10,17,23,27] and the reported evaporators showed much lower vapor yields under weaker natural sunlight conditions. [17,19,23] Thus developing evaporators with high vapor yields under weaker solar irradiations is expected for practical applications. Meanwhile, the fundamental evaporation mechanisms at the evaporator interface have rarely been studied, [25] which will conduct the reasonable design of the evaporator structure with high SVG performance. Inspired by previous work about increased-up water flux in the confined hydrophobic nanochannels, [28,29] we designed nanoconfined water molecule channels (NCWMCs) to achieve high-yield SVG under weaker sunlight. Here, we synthesized a 1D-O-doped MoS 2−x nanosheets assembly (1D-OMoSNSA) via a one-pot solvothermal approach. In the structure of 1D-OMo-SNSA, the gaps formed during stacking were conducive to rapid water transport, and the NCWMC of 3.5 nm spacing between ultrathin O-MoS 2−x nanosheets could reduce water vaporization enthalpy by facilitating water molecules to evaporate as clusters. After heat loss management, this evaporator showed the SVG rate of 2.50 kg m −2 h −1 under 1 sun with the energy efficiency of 89.6%. Furthermore, under weaker natural sunlight irradiation (0.5 sun), the SVG rate could reach 1.25 kg m −2 h −1 , which exceeded the highest reported value, [23] and was comparable with most reported vapor yields at 1 sun. [6-11,13-15,17,19] Molecular dynamics (MD) simulations revealed that this unique performance could be ascribed to the cluster-evaporation process in the NCWMC system. This evaporator was further applied for the practical water purification procedure, and exhibited excellent performance in both seawater desalination and wastewater treatment. The 1D-OMoSNSA was prepared via a simple one-pot solvothermal approach, in which ammonium heptamolybdate (AHM) and thiourea were used as precursors, and oleylamine was used as surfactant. In a typical synthesized process, AHM and thiourea were first dissolved in deionized water, followed by mixed with terpineol and oleylamine. The mixture was sealed in an autoclave and heated at 200 °C for 6 h, and the product was washed by ethanol (for the detailed synthesized process, see Experimental Section). Figure 1a showed the powder X-ray diffraction (XRD) pattern of the prepared product. Compared with

Their highly functional nature has endowed metal-organic frameworks (MOFs) with diverse applications. On this basis, a higher demand has been proposed for the preparation of novel-structured MOFs. Hollow MOFs have been intensively studied and exhibited versatile properties, and among the various methods, secondary-component incorporation has been proved promising in the design and preparation of complex structures with requisite properties. Herein, the synthesis and applications of secondary component incorporated MOFs and their derivatives are systematically reviewed. Two main methodologies, preincorporation and postmodification, are discussed in detail, and the role of the secondary component is demonstrated. Based on these introductions, the applications of those materials, including chemical catalysis, electrocatalysis, and energy storage applications, are summarized. Finally, a personal outlook for the future opportunities and challenges in this field is given.

Well-designed hybrid materials based on noble metal-free elements have great potential to generate hydrogen (H ) and oxygen (O ) sustainably via overall water splitting for developing practical energy-related technologies. Herein, an accessible method is presented to synthesize nickel diselenide (NiSe ) ultrathin nanowires decorated with amorphous nickel oxide nanoparticles (NiO NPs) as multifunctional electrocatalysts (NSWANs) for hydrogen and oxygen evolution reaction (HER and OER). The NSWANs exhibit quite low HER and OER overpotentials of 174 and 295 mV, respectively, holding the current density of 20 mA cm for 24 h continuous operations in alkaline media. Meanwhile, a cell voltage of 1.547 V at the current density of 10 mA cm for overall water splitting has been achieved by the NSWANs for the practical application, which could maintain fascinating activity of 20 mA cm for 72 h without degradation. The decorated NiO NPs not only prevent the NiSe from further oxidation but also expose requisite active sites for electrocatalytic process. It is believed that this study may provide a valuable strategy to design high-efficiency electrocatalysts and expand the applications of selenide-based materials.

Inspired by the success of graphene, a series of single‐ or few‐layer 2D materials have been developed and applied in the past decade. Here, the successful preparation of monolayer and bilayer 2D porphyrin‐based metal–organic frameworks (MOFs) by a facile solvothermal method is reported. The structure transition from monolayer to bilayer drives distinct electronic properties and restructuring behaviors, which finally results in distinct catalytic pathways towards CO2 electrocatalysis. The monolayer favors CO2‐to‐C2 pathway due to the restructuring of CuO4 sites, while CO and HCOO− are the major products over the bilayer. In photocoupled electrocatalysis, the Faradaic efficiency (FE) of the C2 compounds shows a nearly fourfold increase on the monolayer than that under dark conditions (FEC2 increases from 11.9% to 41.1% at −1.4 V). For comparison, the light field plays a negligible effect on the bilayer. The light‐induced selectivity optimization is investigated by experimental characterization and density functional theory (DFT) calculations. This work opens up a novel possibility to tune the selectivity of carbon products just by tailoring the layer number of the 2D material.

Developing efficient and robust heterogeneous metallophthalocyanine electrocatalysts for CO 2 reduction remains a challenge. Here, a general synthetic method of zinc−metallophthalocyanine (MPc) molecular layer/polyoxometalate (POM) sandwich lamellar material is developed, and thus improved performance of electrocatalytic and photocoupled electrocatalytic CO 2 reduction is achieved. The incorporation of POM could prevent the packing of MPc molecular layers from aggregation, which would be favorable to the exposure of active sites. The molecular layer sandwich catalyst presents superior CO 2 reduction activity, delivering the highest CO Faradaic efficiency (FE CO ) of 96.1% at −0.7 V vs RHE in dark field. Under light irradiation, over 93% FE CO is achieved in a broad potential range from −0.6 to −0.9 V vs RHE with a maximum of 96.2%, and the carbon monoxide turnover frequency could exceed 2060 h −1 . Photoelectrochemical tests and luminescence characterizations reveal the molecular layer is beneficial for carrier separation during light irradiation; density functional theory calculations and electron paramagnetic resonance indicated a 2-fold enhancement of the external light field on the catalytic performance.