In Situ Construction of CuTCPP/Bi4O5Br2 Hybrids for Improved Photocatalytic CO2 and Cr(VI) Reduction.

Global warming and heavy metal pollution pose tremendous challenges to human development, and photocatalysis is considered to be an effective strategy to solve these problems. Herein, copper(II) tetra (4-carboxyphenyl) porphyrin (CuTCPP) molecules were successfully in situ loaded onto Bi4O5Br2 by a hydrothermal approach. A series of experimental results show that the light absorption capacity and photogenerated carrier separation efficiency were synchronously enhanced after the construction of CuTCPP/Bi4O5Br2 composites. Hence, the as-prepared composites possess significantly improved photocatalytic ability for both CO2 and Cr(VI) reduction. Specifically, CuTCPP/Bi4O5Br2-2 achieves a CO generation rate of 17.14 µmol g-1 under 5 h irradiation, which is twice as high as that of Bi4O5Br2 (8.57 µmol g-1). Besides, the optimized CuTCPP/Bi4O5Br2-2 also exhibits a removal rate of 61.87% for Cr(VI) within 100 min under irradiation. Furthermore, the mechanism of CO2 and Cr(VI) photoreduction was explored by in situ Fourier transform infrared spectroscopy and capture experiments, respectively. This work can be a reference toward the construction of photocatalysts with high activity for solar energy conversion.

Edge-Site-Rich Ordered Macroporous BiOCl Triggers CO Activation for Efficient CO2 Photoreduction.

Endowing a semiconductor with tunable edge active sites will effectively enhance catalytic performance. Herein, an edge-site-rich ordered macroporous BiOCl (BiOCl-P) with abundant dangling bonds is constructed via the colloidal crystal template method. The edge-site-rich ordered macroporous structure provides abundant adsorption sites for CO2 molecules, as well as forms numerous localized electron enrichment areas, accelerating charge transfer. DFT calculations reveal that the dangling bonds-rich configuration can effectively reduce the CO2 activation energy barrier, boost the CO double bond dissociation, and facilitate the proton electron coupling reaction. As a result, the BiOCl-P achieves a higher CO and CH4 generation rate of 78.07 and 3.03 µmol g-1 under 4 h Xe lamp irradiation in a solid-gas system. Finally, the CO2 molecules' conversion process is further investigated by in situ Fourier-transform infrared spectroscopy. This work realizes a new avenue toward the design of vibrant semiconductors on the nanoscale to boost inert CO2 photoreduction.

Defect-Rich Bi12 O17 Cl2 Nanotubes Self-Accelerating Charge Separation for Boosting Photocatalytic CO2 Reduction.

Solar-driven reduction of CO2 , which converts inexhaustible solar energy into value-added fuels, has been recognized as a promising sustainable energy conversion technology. However, the overall conversion efficiency is significantly limited by the inefficient charge separation and sluggish interfacial reaction dynamics, which resulted from a lack of sufficient active sites. Herein, Bi12 O17 Cl2 superfine nanotubes with a bilayer thickness of the tube wall are designed to achieve structural distortion for the creation of surface oxygen defects, thus accelerating the carrier migration and facilitating CO2 activation. Without cocatalyst and sacrificing reagent, Bi12 O17 Cl2 nanotubes deliver high selectivity CO evolution rate of 48.6 µmol g-1 h-1 in water (16.8 times than of bulk Bi12 O17 Cl2 ), while maintaining stability even after 12 h of testing. This paves the way to design efficient photocatalysts with collaborative optimizing charge separation and CO2 activation towards CO2 photoreduction.

Carbon Quantum Dots Induced Ultrasmall BiOI Nanosheets with Assembled Hollow Structures for Broad Spectrum Photocatalytic Activity and Mechanism Insight.

Carbon quantum dots (CQDs) induced ultrasmall BiOI nanosheets with assembled hollow microsphere structures were prepared via ionic liquids 1-butyl-3-methylimidazolium iodine ([Bmim]I)-assisted synthesis method at room temperature condition. The composition, structure, morphology, and photoelectrochemical properties were investigated by multiple techniques. The CQDs/BiOI hollow microspheres structure displayed improved photocatalytic activities than pure BiOI for the degradation of three different kinds of pollutants, such as antibacterial agent tetracycline (TC), endocrine disrupting chemical bisphenol A (BPA), and phenol rhodamine B (RhB) under visible light, light above 580 nm, or light above 700 nm irradiation, which showed the broad spectrum photocatalytic activity. The key role of CQDs for the improvement of photocatalytic activity was explored. The introduction of CQDs could induce the formation of ultrasmall BiOI nanosheets with assembled hollow microsphere structure, strengthen the light absorption within full spectrum, increase the specific surface areas and improve the separation efficiency of the photogenerated electron-hole pairs. Benefiting from the unique structural features, the CQDs/BiOI microspheres exhibited excellent photoactivity. The h(+) was determined to be the main active specie for the photocatalytic degradation by ESR analysis and free radicals trapping experiments. The CQDs can be further employed to induce other nanosheets be smaller. The design of such architecture with CQDs/BiOI hollow microsphere structure can be extended to other photocatalytic systems.

α-Fe2O3 cubes with high visible-light-activated photoelectrochemical activity towards glucose: hydrothermal synthesis assisted by a hydrophobic ionic liquid.

A liquid/liquid interfacial reaction system was designed to fabricate α-Fe2O3 cubes. The reaction system uses a hydrophobic ionic liquid containing iron ions ([(C8H17)2(CH3)2N]FeCl4) for manufacturing α-Fe2O3 cubes by a novel and environmentally friendly hydrothermal method under low-temperature conditions (140 °C). The iron-containing ionic liquid is hydrophobic and can form a liquid/liquid interface with water, which is vital for fabrication of the α-Fe2O3 cubes. Nanomaterials synthesized from hydrophobic iron-containing ionic liquids show good crystallinity, well-developed morphology, and uniform size. The effect of different ionic liquids on the morphology of α-Fe2 O3 was investigated in detail. [(C8H17)2(CH3)2N]FeCl4 is assumed to perform the triple role of forming a liquid/liquid interface with water and acting as reactant and template at the same time. The effect of the reaction temperature on the formation of the α-Fe2O3 cubes was also studied. Temperatures lower or higher than 140 °C are not conducive to formation of the α-Fe2O3 cubes. Their photoelectrochemical properties were tested by means of the transient photocurrent response of electrodes modified with as-prepared α-Fe2O3 cubes. The photocurrent response of an α-Fe2O3 cubes/indium tin oxide electrode is high and stable, and it shows great promise as a photoelectrochemical glucose sensor with high sensitivity and fast response, which are beneficial to practical applications of nanosensors.

Synthesis, characterization and photocatalytic activity of Ag/AgCl/graphite-like C3N4 under visible light irradiation.

A new type of Ag/AgCl/g-C3N4 composite could be facilely fabricated. The techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectra (FT-IR) were used to characterize the phase and structure of the samples. The activity of the Ag/AgCl/g-C3N4 composites for photodegradation of methyl orange (MO) was higher than that of either the pure g-C3N4 or Ag/AgCl. DRS of Ag/AgCl/g-C3N4 composites exhibited strong absorbance in the visible region due to the localized surface plasmon resonance (LSPR) absorption of metal Ag nanomaterial. The enhancement of photocatalytic activity of the Ag/AgCI/g-C3N4 composites was attributed to the effective charge transfer from plasmon-excited Ag to AgCI, which suppressed the charge recombination during photocatalytic reaction process.

Low concentration of peroxymonosulfate coupled with visible light triggers oxygen reactive species generation over constructed Bi25FeO40/BiOCl Z-scheme heterojunction for various tetracycline antibiotics removal.

Photocatalytic peroxymonosulfate (PMS) oxidation systems demonstrate significant potential and promising prospects through the interconnection of photocatalytic and PMS oxidation for simultaneously achieving efficient pollutant removal and reduction of PMS dosage, which prevents resource wastage and secondary pollution. In this study, a Z-scheme Bi25FeO40/BiOCl (BOFC) heterojunction was constructed to carry out the photocatalytic PMS oxidation process for tetracyclines (TCs) pollutants at low PMS concentrations (0.08 mM). The photocatalytic PMS oxidation rate of Bi25FeO40/BiOCl composites for tetracycline hydrochloride (TCH), chlortetracycline (CTC), oxytetracycline (OTC) and doxycycline (DXC) reaches 86.6%, 83.6%, 86.7%, and 88.0% within 120 min. Simultaneously, the BOFC/PMS system under visible light (Vis) equally displayed the practical application prospects for the solo and mixed simulated TCs antibiotics wastewater. Based on the electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) valence band spectrum, a Z-scheme electron migration pathway was proposed to elucidate the mechanism underlying the performance enhancement of BOFC composites. Bi25FeO40 in BOFC composites can serve as active site for activating PMS by the formation of Fe3+/Fe2+ cycle. Toxicity estimation software tool (T.E.S.T.) and mung beans planting experiment demonstrates that BOFC/PMS/Vis system can reduce toxicity of TCs wastewater. Therefore, BOFC/PMS/Vis system achieves efficient examination in different water environments and efficient utilization of PMS, which displays a scientific reference for achieving environmentally-friendly and resource-saving handling processes.

Strain-Induced Surface Interface Dual Polarization Constructs PML-Cu/Bi12O17Br2 High-Density Active Sites for CO2 Photoreduction.

The insufficient active sites and slow interfacial charge transfer of photocatalysts restrict the efficiency of CO2 photoreduction. The synchronized modulation of the above key issues is demanding and challenging. Herein, strain-induced strategy is developed to construct the Bi-O-bonded interface in Cu porphyrin-based monoatomic layer (PML-Cu) and Bi12O17Br2 (BOB), which triggers the surface interface dual polarization of PML-Cu/BOB (PBOB). In this multi-step polarization, the built-in electric field formed between the interfaces induces the electron transfer from conduction band (CB) of BOB to CB of PML-Cu and suppresses its reverse migration. Moreover, the surface polarization of PML-Cu further promotes the electron converge in Cu atoms. The introduction of PML-Cu endows a high density of dispersed Cu active sites on the surface of PBOB, significantly promoting the adsorption and activation of CO2 and CO desorption. The conversion rate of CO2 photoreduction to CO for PBOB can reach 584.3 µmol g-1, which is 7.83 times higher than BOB and 20.01 times than PML-Cu. This work offers valuable insights into multi-step polarization regulation and active site design for catalysts.

Acceleration of Photoinduced Electron Transfer by Modulating Electronegativity of Substituents in Stable Zr-Metal-Organic Frameworks to Boost Photocatalytic CO2 Reduction.

Photoreduction of CO2 with water into chemical feedstocks of fuels provides a green way to help solve both the energy crisis and carbon emission issues. Metal-organic frameworks (MOFs) show great potential for CO2 photoreduction. However, poor water stability and sluggish charge transfer could limit their application. Herein, three water-stable MOFs functionalized with electron-donating methyl groups and/or electron-withdrawing trifluoromethyl groups are obtained for the CO2 photoreduction. Compared with UiO-67-o-CF3-CH3 and UiO-67-o-(CF3)2, UiO-67-o-(CH3)2 achieves excellent performance with an average CO generation rate of 178.0 µmol g-1 h-1 without using any organic solvent or sacrificial reagent. The superior photocatalytic activity of UiO-67-o-(CH3)2 is attributed to the fact that compared with trifluoromethyl groups, methyl groups could not only elevate CO2 adsorption capacity and reduction potential but also promote photoinduced charge separation and migration. These are evidenced by gas physisorption, photoluminescence, time-resolved photoluminescence, electrochemical impedance spectroscopy, transient photocurrent characteristics, and density functional theory calculations. The possible working mechanisms of electron-donating methyl groups are also proposed. Moreover, UiO-67-o-(CH3)2 demonstrates excellent reusability for the CO2 reduction. Based on these results, it could be affirmed that the strategy of modulating substituent electronegativity could provide guidance for designing highly efficient photocatalysts.

Semimetallic Bismuthene with Edge-Rich Dangling Bonds: Broad-Spectrum-Driven and Edge-Confined Electron Enhancement Boosting CO2 Hydrogenation Reduction.

Broad-spectrum-driven high-performance artificial photosynthesis is quite challenging. Herein, atomically ultrathin bismuthene with semimetallic properties is designed and demonstrated for broad-spectrum (ultraviolet-visible-near infrared light) (UV-vis-NIR)-driven photocatalytic CO2 hydrogenation. The trap states in the bandgap produced by edge dangling bonds prolong the lifetime of the photogenerated electrons from 90 ps in bulk Bi to 1650 ps in bismuthine, and excited-state electrons are enriched at the edge of bismuthine. The edge dangling bonds of bismuthene as the active sites for adsorption/activation of CO2 increase the hybridization ability of the Bi 6p orbital and O 2p orbital to significantly reduce the catalytic reaction energy barrier and promote the formation of C─H bonds until the generation of CH4. Under λ ≥ 400 nm and λ ≥ 550 nm irradiation, the utilization ratios of photogenerated electron reduction CO2 hydrogenation to CO and CH4 for bismuthene are 58.24 and 300.50 times higher than those of bulk Bi, respectively. Moreover, bismuthene can extend the CO2 hydrogenation reaction to the near-infrared region (λ ≥ 700 nm). This pioneering work employs the single semimetal element as an artificial photosynthetic catalyst to produce a broad spectral response.

AgX/graphite-like C(3)N(4) (X = Br, I) hybrid materials for photoelectrochemical determination of copper(II) ion.

A novel photoelectrochemical strategy has been designed for the detection of Cu(2+) with AgX/g-C3N4 (X = Br, I) hybrid materials. The present study can serve as a foundation for the application of AgX/g-C3N4 hybrid materials in photoelectron-chemical ion sensing. It can be successfully applied to the detection of copper in human hair samples.

A novel Sillén-structured Bi-based oxybromide: CdBiO2Br ultrathin nanosheets for enhanced photocatalytic activity.

According to the typical Sillén-structured BiOBr, a simple solvothermal method was used to successfully synthesise Sillén-structured bimetallic oxyhalide CdBiO2Br with the existence of 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br), a kind of reactive ionic liquid. The introduction of the metal cadmium, which can form Sillén-structured bimetallic oxyhalide, made the alternating structure of BiOBr originally [Bi2O2]2+ and bilayer Br- modified to that of [CdBiO2]+ and monolayer Br-. So that the distance between layer and layer is greatly shortened, which facilitates the migration and separation of photogenerated carriers and promotes the generation of more reactive oxygen species. After modification, the band positions of CdBiO2Br materials can make more full use of visible light and more favourable utilisation of solar resources. As confirmed by radical trapping analysis and ESR analysis, superoxide radical (·O2-) and hole (h+) acted the major part during photocatalysis. The possible intermediate products that appeared during the degradation progress were analyzed by LC-MS. Moreover, the generation of superoxide ions was quantitatively analyzed by nitroblue tetrazolium chloride (NBT). In this paper, we present an ultra-thin layered material for visible light catalysis, which enlightens a feasible scheme for the research and development of new layered photocatalytic materials.

Synergy between plasmonic and sites on gold nanoparticle-modified bismuth-rich bismuth oxybromide nanotubes for the efficient photocatalytic CC coupling synthesis of ethane.

The photocatalytic reduction of carbon dioxide (CO2) to fossil fuels has attracted widespread attention. However, obtaining the high value-added hydrocarbons, especially C2+ products, remains a considerable challenge. Herein, gold (Au) nanoparticle-modified bismuth-rich bismuth oxybromide Bi12O17Br2 nanotube composites were designed and tested. Au nanoparticles act as electron traps and thermal electron donors that promote the efficient separation and migration of carriers to form the C2+ product. As a result, compared with the pure Bi12O17Br2 nanotubes, Au@Bi12O17Br2 composites can not only produce the carbon monoxide (CO) and methane (CH4), but also covert CO2 into ethane (C2H6). In this study, Au@Bi12O17Br2-700 was used to obtain a C2H6 production rate of 29.26 µmol h-1 g-1. The selectivities during a 5-hour test reached 94.86% for hydrocarbons and 90.81% for C2H6. The proposed approach could be used to design high-performance photocatalysts to convert CO2 into high value-added hydrocarbon products.

Oxygen vacancies mediated Bi12O17Cl2 ultrathin nanobelts: Boosting molecular oxygen activation for efficient organic pollutants degradation.

Photocatalysis technology has been considered as a sustainable and promising strategy for pollutant degradation. However, the photocatalytic activity is limited by the unsatisfactory carrier separation efficiency of photocatalysts and insufficient reactive oxygen species. Herein, the oxygen vacancies (OVs) mediated Bi12O17Cl2 ultra-thin nanobelt (ROV Bi12O17Cl2) was fabricated via solvothermal method. The surface oxygen vacancies can act as the 'electron sink' and boost charge separation. Thus, the ROV Bi12O17Cl2 shows superior photocatalytic performance, which is 2.72 and 4.52 times compared to deficient oxygen vacancies Bi12O17Cl2 (DOV Bi12O17Cl2) and Bulk Bi12O17Cl2 for colored organic pollutants degradation, respectively. Besides, the ROV Bi12O17Cl2 also displays excellent removal efficiency for refractory antibiotics, roughly 4.00 and 7.45 times compared to that of DOV Bi12O17Cl2 and Bulk Bi12O17Cl2, respectively. Furthermore, the intermediates for photocatalytic degradation were determined through HPLC-MS and the possible degradation paths of the target molecules were inferred. Capture experiment and ESR spectra confirmed that the •O2- played a vital role for the organic pollutant degradation. This work provides a new perspective for the design of advanced semiconductors for organic pollutants degradation.

Oxygen vacancy triggering the broad-spectrum photocatalysis of bismuth oxyhalide solid solution for ciprofloxacin removal.

The construction of a broad-spectrum photocatalytic system is of great significance for maximizing the utilization of solar energy. Herein, a surface oxygen vacancy triggering high-efficient broad-spectrum BiOCl0.5I0.5 solid solution photocatalyst was successfully fabricated via a one-pot solvothermal process. The UV-vis diffuse reflectance spectra revealed that the introduced oxygen vacancy appears to extend the absorption region of BiOCl0.5I0.5 to a wider wavelength range. Under λ > 580 nm light irradiation for 5 h, nearly 85.6% ciprofloxacin was degraded by BiOCl0.5I0.5 with rich oxygen vacancy, the ciprofloxacin removal efficiency was 3.4 times higher than that with less oxygen vacancy. Moreover, the density functional theory calculations and photoelectrochemical characterizations indicated the excited electrons would preferentially transfer to the new defect level induced by oxygen vacancy, thus greatly reducing the recombination of photogenerated carriers. This work tends to deepen the understanding of defect engineering in steering the construction of broad-spectrum Bi-based solid solution photocatalysts as well as its application in environmental remediation.

Dual modulation steering electron reducibility and transfer of bismuth molybdate nanoparticle to boost carbon dioxide photoreduction to carbon monoxide.

Owing to the exorbitant CO2 activation energy and unsatisfactory photogenerated charge separation efficiency, CO2 photoconversion still faces enormous challenges. In this study, a directional electron transfer channel has been established by decorating N-doped carbon quantum dots (N-CQDs) on the surface of Bi4MoO9 nanoparticles to ensure that more active electrons can participate in the CO2 reduction. The conduction band of Bi4MoO9 nanoparticles is calculated to be -1.55 eV versus the normal hydrogen electrode (NHE), pH = 7, which is negative enough to attain the photocatalytic CO2 reduction potential of -0.53 eV versus NHE, pH = 7. CO2 adsorption curves and in situ Fourier transform infrared spectra reveal that N-CQDs facilitate surface CO2 adsorption and activation, as well as CO desorption. In addition, steady-state photoluminescence and photoelectrochemical tests prove that the charge separation efficiency can be greatly enhanced by constructing N-CQDs/Bi4MoO9 composites. In the presence of pure water, N-CQDs/Bi4MoO9-2 composite achieved a CO yield of 16.22 µmol g-1 after 5 h Xe light illumination, which was 3.24 times higher than that of pure Bi4MoO9 (4.98 µmol g-1). This study offers a distinctive approach to the optimization of Bi4MoO9 photocatalysts and their application in energy conversion.

Polarized Cu-Bi Site Pairs for Non-Covalent to Covalent Interaction Tuning toward N2 Photoreduction.

A universal atomic layer confined doping strategy is developed to prepare Bi24 O31 Br10 materials incorporating isolated Cu atoms. The local polarization can be created along the CuOBi atomic interface, which enables better electron delocalization for effective N2 activation. The optimized Cu-Bi24 O31 Br10 atomic layers show 5.3× and 88.2× improved photocatalytic nitrogen fixation activity than Bi24 O31 Br10 atomic layer and bulk Bi24 O31 Br10 , respectively, with the NH3 generation rate reaching 291.1 µmol g-1 h-1 in pure water. The polarized Cu-Bi site pairs can increase the non-covalent interaction between the catalyst's surface and N2 molecules, then further weaken the covalent bond order in NN. As a result, the hydrogenation pathways can be altered from the associative distal pathway for Bi24 O31 Br10 to the alternating pathway for Cu-Bi24 O31 Br10 . This strategy provides an accessible pathway for designing polarized metal site pairs or tuning the non-covalent interaction and covalent bond order.

Self-assembly and enhanced photocatalytic properties of BiOI hollow microspheres via a reactable ionic liquid.

BiOI uniform flowerlike hollow microspheres with a hole in its surface structures have been successfully synthesized through an EG-assisted solvothermal process in the presence of ionic liquid 1-butyl-3-methylimidazolium iodine ([Bmim]I). The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), nitrogen sorption, and diffuse reflectance spectroscopy (DRS). A possible formation mechanism for the growth of hollow microspheres was discussed. During the reactive process, ionic liquid not only acted as solvents and templates but also as an I source for the fabrication of BiOI hollow microspheres and was vital for the structure of hollow microspheres. Additionally, we evaluated the photocatalytic activities of BiOI on the degradation of methyl orange (MO) under visible light irradiation and found that as-prepared BiOI hollow microspheres exhibited higher photocatalytic activity than BiOI nanoplates and TiO(2) (Degussa, P25) did. On the basis of such analysis, it can be assumed that the enhanced photocatalytic activities of BiOI hollow microspheres could be ascribed to its energy band structure, high BET surface area, high surface-to-volume ratios, and light absorbance.

Tuning the Active Sites of Atomically Thin Defective Bi12O17Cl2 via Incorporation of Subnanometer Clusters.

The introduction of subnanometer clusters as active sites on the surface of photocatalysts for efficiently tuning the selectivity and activity of the photocatalyts is still a challenge. Herein, the subnanometer Ag/AgCl clusters were incorporated on atomically thin defective Bi12O17Cl2 nanosheets via rebinding with unsaturated Cl atoms. Benefiting from the surficial Bi vacancies (VBi) and Bi-O vacancies (VBi-O) in this atomically thin architecture, the local atomic arrangement was tuned so that the subnanometer Ag/AgCl clusters were successfully incorporated. An enhancement of photocatalytic activity for NO removal was achieved in which the activity is 3 times higher than that of Bi12O17Cl2 and 1.8 times higher than that of defective Bi12O17Cl2. The substitution of the active sites from surficial VBi and VBi-O to be subnanometer Ag/AgCl clusters enables a tunable redox potential and different reaction mechanisms in NO removal. Moreover, the selectivity of the photoinduced redox reaction on NO oxidation and CO2 reduction was achieved via introducing an extra energy level.

A Janus cobalt nanoparticles and molybdenum carbide decorated N-doped carbon for high-performance overall water splitting.

The fabrication of high-performance and stable electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of importance for sustainable water-splitting technologies. Herein, the cobalt (Co) nanoparticles and molybdenum carbide (Mo2C) heterostructures anchored N-doped carbon (Co/Mo2C@NC-800) was designed as bifunctional electrocatalyst for overall water splitting via a simple pyrolysis approach for metal organic frameworks (MOFs) precursor. This composite shows a remarkable performance for HER and OER with a small overpotential of 121 mV and 311 mV at 10 mA cm-2, respectively. When the optimized electrocatalyst was employed as both anode and cathode for overall water splitting in a two-electrode system, the electrolyzer achieves a low cell voltage of 1.67 V at 10 mA cm-2 in 1 M KOH, as well as a superior and stable long-time operation of 30 h. The promising hybrid material demonstrates excellent electrocatalysis performance due to effective combination of the best of both worlds: Mo2C with remarkable HER performance and Co nanoparticles with excellent OER activity. The Mo2C possesses strong hydrogen binding energy and Co exhibits prominent electrical conductivity, thus the construction of heterostructures achieves more active sites with different functions and significantly boosts HER and OER process. The novel and effective synthesis strategy provides new insights into the design of outstanding non-noble metal bifunctional electrocatalysts for overall water splitting.