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Polycyclic aromatic hydrocarbons (PAHs) are persistent and widespread in the aquatic environment, causing potential hazards for human health. In this study, a superwetting and robust PES-PAA-ZrO2 nanofiltration membrane was proposed through surface modification for PAH removal with high efficiency. A ZrO2 coating was formed on polyethersulfone (PES) membrane surface through chemical bonding, thus the PES-PAA-ZrO2 membrane exhibited super-hydrophilicity, under-water oleophobicity, and excellent stability. In comparison with the original PES membrane, the water contact angle of the modified membrane was significantly decreased from about 50° to less than 10°, and quickly dropped to 0° within 1 s. This provided a much lower energy barrier for water permeation due to its super-high water affinity. The wastewater treatment efficiency was increased by about 4 times after modification with more than 90% of PAH rejection rate. The excellent robustness of PES-PAA-ZrO2 membrane was verified under various conditions, which gave the membrane practical potential for long-term operation.

The widespread cellulose nanomaterials from industrial production and natural plant degradation inevitably lead to the accumulation of nanocellulose in aquatic environment. However, the effect of nanocellulose on the fate, transport and biotoxicity of zinc oxide nanoparticles (ZnO NPs) remains largely unexplored. The present study investigated the interactions between nanocellulose and ZnO NPs. The addition of naturally-derived cellulose nanocrystals (CNCs) significantly reduced the aggregation of ZnO NPs, resulting in enhanced bioavailability and toxicity to the algae Eremosphaera viridis. The ZnO-CNC association enhanced the envelopment of the algal cells and exerted strong oxidative stress as compared to bare ZnO NPs. The excessive reactive oxygen species generation could result in the breakdown of membrane lipid and disruption of antioxidant enzyme activity, where the lipid synthesis was inhibited and protein folding might occur. The presence of CNC also improved the concentration of Zn ions inside the algal cell through intracellular transportation. This can affect the flow of substances between algae cells and the environment, and further influence the metabolism of microalgae. This work is crucial for improving our insight into the mechanism for combined effects from multiple nanomaterials, such that the composite risks of such combined effects to aquatic organisms can be identified.

Biomolecules with a broad range of structure and heteroatom-containing groups offer a great opportunity for rational design of promising electrocatalysts via versatile chemistry. In this study, uniform folic acid–Co nanotubes (FA–Co NTs) were hydrothermally prepared as sacrificial templates for highly porous Co and N co-doped carbon nanotubes (Co–N/CNTs) with well-controlled size and morphology. The formation mechanism of FA–Co NTs was investigated and FA–Co-hydrazine coordination interaction together with the H-bond interaction between FA molecules was characterized to be the driving force for growth of one-dimensional nanotubes. Such distinct metal–ligand interaction afforded the resultant CNTs rich Co–Nx sites, hierarchically porous structure and Co nanoparticle-embedded conductive network, thus an overall good electrocatalytic activity for oxygen reduction. Electrochemical tests showed that Co–N/CNTs-900 promoted an efficient 4e− ORR process with an onset potential of 0.908 V vs. RHE, a limiting current density of 5.66 mA cm−2 at 0.6 V and a H2O2 yield lower than 5%, comparable to that of 20% Pt/C catalyst. Moreover, the catalyst revealed very high stability upon continuous operation and remarkable tolerance to methanol.

Copper (Cu) products, including copper oxide nanoparticles (nCuO), are critically important agricultural fungicides and algaecides. Foliar application onto crops and subsequent aerosol drift of these Cu products, especially nCuO, on to soil may alter nutrient cycling and microbial communities in both managed and unmanaged environments. We measured the influence of land use on soil microbial biomass and respiration in response to the addition of nCuO to an alluvial soil. Different land uses included grassland, forest and both organic and conventional managed row crops. Soil samples were amended with 1000 mg Cu per kg soil as CuCl2, 16 nm CuO (16nCuO), 42 nm CuO (42nCuO), and larger than nanoparticle sized bulk CuO (bCuO). Copper availability immediately increased in all soils following Cu addition in the order of CuCl2 > 16nCuO > 42nCuO > bCuO. After 70 days Cu availability was diminished across land uses and lowest in soils treated with bCuO. Using X-ray absorption near edge structure (XANES) spectroscopy, we determined that the relatively high availability of Cu after treatment with nanoparticle sized CuO was due to the dissolution of CuO particles and subsequent adsorption by soil materials. Respiration, an indicator of microbial activity, was suppressed by Cu additions, especially CuCl2. Copper effects on soil microbial biomass were sensitive to land use. In agricultural soils, microbial biomass was unaltered by Cu form, regardless of concentration, whereas in unmanaged soils, it decreased following exposure to CuCl2 and 42nCuO. Our results suggest that land use history has little impact on Cu chemical fate in soils, but strongly modulates microbial response to Cu exposure. These results are especially important for organic agricultural systems where copper fungicides are widely used but may suppress microbial mineralization of nutrients from soil organic matter.

Stable solid electrolyte interface (SEI) is highly sought after for lithium metal batteries (LMB) owing to its efficient electrolyte consumption suppression and Li dendrite growth inhibition. However, current design strategies can hardly endow a multifunctional SEI formation due to the non-uniform, low flexible film formation and limited capability to alter Li nucleation/growth orientation, which results in unconstrained dendrite growth and short cycling stability. Herein, we present a novel strategy to employ electrolyte additives containing catechol and acrylic groups to construct a stable multifunctional SEI by in-situ anionic polymerization. This self-smoothing and robust SEI offers multiple sites for Li adsorption and steric repulsion to constrain nucleation/growth process, leading to homogenized Li nanosphere formation. This isotropic nanosphere offers non-preferred Li growth orientation, rendering uniform Li deposition to achieve a dendrite-free anode. Attributed to these superiorities, a remarkable cycling performance can be obtained, i.e., high current density up to 10 mA cm−2, ultra-long cycle life over 8500 hrs operation, high cumulative capacity over 4.25 Ah cm−2 and stable cycling under 60 °C. A prolonged lifespan can also be achieved in Li-S and Li-LiFePO4 cells under lean electrolyte content, low N/P ratio or high temperature conditions. This facile strategy also promotes the practical application of LMB and enlightens the SEI design in related fields., Stable solid electrolyte interface (SEI) is heavily investigated due to its role in improving lithium metal batteries. Here, the authors present a new strategy by employing electrolyte additives to construct stable multifunctional SEI via in situ anionic polymerization.

Genetic models for the formation of uranium deposits almost invariably invoke the reduction of U(VI) to U(IV) as the deposition mechanism. However, the questions of when and how this reduction occurred are often not clear in most uranium deposits. For example, mineralization in the giant Olympic Dam Cu-U-Au-Ag deposit (Australia) occurs mainly in hematite-rich breccias of the oxidizing hematite-quartz-barite assemblage. Similarly, unconformity-related uranium deposits in the Athabasca Basin (Canada) are accompanied by extensive and intensive hematite- and quartz-rich alteration halos, pointing to a possible linkage between uranium mineralization and silicification. However, this linkage is not understood due to the lack of knowledge about the speciation and mechanism of uranium incorporation in microcrystalline and macrocrystalline silicas. In this contribution, microcrystalline silicas (agate and opal-CT) containing 27–137 ppm U have been investigated by microbeam synchrotron X-ray fluorescence mapping, microbeam synchrotron X-ray diffraction analysis, synchrotron X-ray absorption spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and electron paramagnetic resonance spectroscopy. These data unravel the binding mechanism of uranyl silicate complexes in microcrystalline silicas and suggest a new mechanism of uranium deposition involving uranyl co-precipitation without the putative reduction process, providing a potential missing link between uranium mineralization and silicification for the formation of uranium deposits. In addition, new data on the uptake and long-term retention of elevated uranyl contents in microcrystalline silicas extend previous findings from their amorphous counterparts on these materials as an effective sink for uranium attenuation to higher temperatures, important to the storage and disposal of heat-generating nuclear waste in deep geological repositories.

Recently, halide solid-state electrolytes (SSEs) have been reported to exhibit high ionic conductivity and good compatibility with cathode materials. However, the air stability of halide-based elec...

The trade-off between energy density and power capabilities is a challenge for Li-ion battery design as it highly depends on the complex porous structures that holds the liquid electrolyte. Specifically, mass-transport limitations lead to large concentration gradients in the solution-phase and subsequently to crippling overpotentials. The direct study of these solution-phase concentration profiles in Li-ion battery positive electrodes has been elusive, in part because they are shielded by an opaque and paramagnetic matrix. Herein we present a new methodology employing synchrotron hard X-ray fluorescence to observe the concentration gradient formation within Li-ion battery electrodes in operando. This methodology is substantiated with data collected on a model LiFePO4/Li cell using a 1 M LiAsF6 in 1:1 ethylene carbonate/dimethyl carbonate (EC/DMC) electrolyte under galvanostatic and intermittent charge profiles. As such, the technique holds great promise for optimization of new composite electrodes and for numerical model validation.

The challenge from pathogenic infections still threatens the health and life of people in developing areas. An efficient, low-cost, and abundant-resource disinfection method is desired for supplying safe drinking water. This study aims to develop a novel Ti

Energy crises, environmental pollution, and freshwater deficiency are critical issues on the planet. Electrolytic hydrogen generation from saline water, particularly from salt-contained hazardous wastewater, is significant to both environment and energy concerns but still challenging due to the high energy cost, severe corrosion, and the absence of competent electrocatalysts. Herein, a novel strategy is proposed for energy-efficient hydrogen production coupled with electro-oxidation removal of ethanolamine pollutant in saline water. To achieve this, an active and durable heterostructured electrocatalyst is developed by in situ growing Ni@Ni

Gypsum is the most common sulfate mineral on Earth's surface and is the dominant solid byproduct in a wide variety of mining and industrial processes, thus representing a major source for heavy metal(loid) contamination, including selenium. Gypsum crystals grown from the gel diffusion technique in 0.02 M Na2SeO4 solution at pH 7.5 and 0.02 M Na2SeO3 solutions at pH 7.5 and 9.0 contain 828, 5198, and 5955 ppm Se, respectively. Synchrotron Se K-edge X-ray absorption spectroscopic analyses show that selenite and selenate are the dominant species in Se4+- and Se6+-doped gypsum, respectively. The single-crystal EPR spectra of Se4+- and Se6+-doped gypsum after gamma-ray irradiation reveal five selenium-centered oxyradicals: SeO2-(I), SeO2-(II), SeO2-(III), SeO3-, and HSeO42-. The former three radicals provide unequivocal evidence for the substitution of their paramagnetic precursor SeO32- for SO42- in the gypsum structure, while the latter two confirm the replacement of SeO42- for SO42-. These results demonstrate that gypsum has a significant capacity for sequestrating both selenite and selenate in the structure but has a marked preference for the former, thus confirming important controls on the mobility and bioavailability of selenium oxyanions and pointing to optimal applications of gypsum for remediating selenium contamination under neutral to alkaline conditions.

Electrochemical reduction of CO2 to value-added products with high selectivity has attracted significant research interest. The development of earth-abundant and low-cost electrocatalysts is the key in this process. Herein, an efficient CO2 reduction electrocatalyst, comprising Ni and N in situ co-doped into porous and Ni nanoparticle-embedded carbon nanotubes (NiNxCNT), is developed from a sustainable and representative bioligand – folic acid. The synthesis process is straightforward, with the crucial step being the chelation of folic acid and Ni ions into uniform tubular metal–organic complex precursor. The resulted NiNxCNT catalyst exhibits a CO partial current density of 9.0 mA cm−2 at −0.676 V versus RHE and a high selectivity towards CO (>98%) in a wide potential range of −0.676 to −0.976 V versus RHE. Furthermore, the electrode shows little current decay over a period of total 44 h continuous operation at different potentials. The notable performance here is attributed to the synergistic effect of rich Ni–Nx sites and hierarchically porous nanotube structure. The findings of this study will open new avenues for developing inexpensive and high-performance CNT-based electrocatalysts for CO2 utilization.

This study investigated the biogeochemistry of uranium (U), and the co-occurring elements nickel (Ni) and arsenic (As), in colloids and sediments from two meromictic mine pit lakes that have considerably different depths and geochemistry. In order to characterize the processes controlling metal speciation and cycling in the pits, the distribution and speciation of the elements in colloidal size fractions were analyzed using micro- and ultrafiltration in combination with transmission electron microscopy. Sediment traps collected fresh sediments over the course of one year below the chemocline of the pit lakes and were subsequently analyzed by scanning electron microscopy (SEM) for morphology and chemical digestions. The most common particles found in the shallower pit consisted of Ca-O and Fe-O colloids, while the particles in the deeper pit were composed of Ca-S-O. Filtration results showed a higher abundance of metals in larger colloidal fractions in aged samples, suggesting that colloids can act as metal accumulators. Sediment traps showed the formation of Fe-O, Fe-S, Al-Si, and Ce-P phases, which were observed to sorb U and Ni. The overall U removal was calculated to be 0.9 g/m2/year in both pits, despite considerably different geochemical conditions between the two, and the maximum removal rates for As (shallow pit) and Ni (deeper pit) were 4.7 g/m2/year and 0.6 g/m2/year, respectively. Bottom sediments were also collected from both pits, and characterized using sequential extractions, SEM, synchrotron-based X-ray absorption spectroscopy and Laue diffraction techniques. These techniques showed that the stability of metals in the sediment follows the order Ni

A super-hydrophilic, polyvinylidene fluoride (PVDF) membrane was obtained through plasma-induced poly (acrylic acid) (PAA) polymerization followed by titanium dioxide nano particles (TiO2 NPs) self-assembly for oily produced water treatment. Fractional factorial design method was applied to investigate the effects of experimental factors and their interactions on membrane modification. The mechanism of TiO2 NPs self-assembly was explored through synchrotron-based X-ray analyses and comprehensive membrane characterization. It was found that nano-TiO2 was immobilized onto the membrane surface through PAA layer without valence change. For the first time, the mechanism of nano-TiO2 immobilization was confirmed to be the coordination of Ti4+ with carboxylic group. After modification, the TiO2 NPs were strongly and uniformly fixed on membrane surface, dramatically improving the hydrophilicity of the PVDF membrane surface. The permeation flux was increased more than four times, and the oil rejection rate was higher than 92%. The modified PVDF membrane has great potential in the application for various water-recovery systems, and this study provided a new insight into the nature of functionalized polymer membrane.

A novel membrane surface modification approach was proposed to successfully obtain a poly(vinylidene fluoride)-poly(acrylic acid)-ZnO (PVDF-PAA-ZnO) membrane with super-high water permeability and great oil rejection through cold plasma-induced PAA graft-polymerization followed by simple nano-ZnO self-assembly. The experimental parameters of modification were optimized and their optimal combination was identified using Taguchi orthogonal array (OA) design method. The PVDF-PAA-ZnO membrane was comprehensively characterized and the mechanism of nano-ZnO self-assembly was explored by contact angle measurement, scanning electron microscope (SEM) images, elemental analysis, tension test, Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and synchrotron-based X-ray analyses. It was revealed that ZnO nanoparticles were immobilized onto membrane surface through the adsorption of PAA layer to form a PAA-ZnO coating without valence change. The carboxyl groups of PAA layer provided complexing ligands to coordinate with Zn2+ and form bidentate species on the nano-ZnO surface. The firm PAA-ZnO coating on PVDF membrane surface converted its hydrophobic nature to hydrophilic, bringing about the dramatically improvement of membrane performance both in water permeation flux and oil rejection rate. The permeation flux of the PVDF-PAA-ZnO membrane was more than 10 times as great as that of the pristine PVDF membrane.

Technetium-99 (99Tc) is a major contaminant at nuclear power plants and several US Department of Energy sites. Its most common aqueous species, pertechnetate (TcO4-), is very mobile in the environment, and currently there are no effective technologies for its sequestration. In this work, a porous iron (pFe) material was investigated for TcO4- and perrhenate (ReO4-) sequestration from artificial groundwater. The pFe was significantly more effective than granular iron for both TcO4- and ReO4- sequestration under oxic conditions. The Tc removal capacity was 27.5 mg Tc/g pFe at pH ˜6.8, while the Re removal capacity was 23.9 mg Re/g pFe at pH ˜10.6. Tc K-edge XANES and EXAFS analyses indicated that the removed Tc species was 70-80% Tc(IV) that was likely incorporated into Fe corrosion products (i.e., Fe(OOH), Fe3O4) and 20-30% unreduced TcO4-. In contrast, the removed Re species was ReO4- only, without detectable Re(IV). In addition, the sequestered ReO4- was not extracted (

The development of all-solid-state Li metal batteries (ASSLMBs) has attracted significant attention due to their potential to maximize energy density and improved safety compared to the conventional liquid-electrolyte-based Li-ion batteries. However, it is very challenging to fabricate an ideal solid-state electrolyte (SSE) that simultaneously possesses high ionic conductivity, excellent air-stability, and good Li metal compatibility. Herein, a new glass-ceramic Li3.2 P0.8 Sn0.2 S4 (gc-Li3.2 P0.8 Sn0.2 S4 ) SSE is synthesized to satisfy the aforementioned requirements, enabling high-performance ASSLMBs at room temperature (RT). Compared with the conventional Li3 PS4 glass-ceramics, the present gc-Li3.2 P0.8 Sn0.2 S4 SSE with 12% amorphous content has an enlarged unit cell and a high Li+ ion concentration, which leads to 6.2-times higher ionic conductivity (1.21 × 10-3 S cm-1 at RT) after a simple cold sintering process. The (P/Sn)S4 tetrahedron inside the gc-Li3.2 P0.8 Sn0.2 S4 SSE is verified to show a strong resistance toward reaction with H2 O in 5%-humidity air, demonstrating excellent air-stability. Moreover, the gc-Li3.2 P0.8 Sn0.2 S4 SSE triggers the formation of Li-Sn alloys at the Li/SSE interface, serving as an essential component to stabilize the interface and deliver good electrochemical performance in both symmetric and full cells. The discovery of this gc-Li3.2 P0.8 Sn0.2 S4 superionic conductor enriches the choice of advanced SSEs and accelerates the commercialization of ASSLMBs.

The W1Mo1-NG dual-atom catalyst enables Pt-like activity and ultrahigh stability for hydrogen evolution reaction., Single-atom catalysts (SACs) maximize the utility efficiency of metal atoms and offer great potential for hydrogen evolution reaction (HER). Bimetal atom catalysts are an appealing strategy in virtue of the synergistic interaction of neighboring metal atoms, which can further improve the intrinsic HER activity beyond SACs. However, the rational design of these systems remains conceptually challenging and requires in-depth research both experimentally and theoretically. Here, we develop a dual-atom catalyst (DAC) consisting of O-coordinated W-Mo heterodimer embedded in N-doped graphene (W1Mo1-NG), which is synthesized by controllable self-assembly and nitridation processes. In W1Mo1-NG, the O-bridged W-Mo atoms are anchored in NG vacancies through oxygen atoms with W─O─Mo─O─C configuration, resulting in stable and finely distribution. The W1Mo1-NG DAC enables Pt-like activity and ultrahigh stability for HER in pH-universal electrolyte. The electron delocalization of W─O─Mo─O─C configuration provides optimal adsorption strength of H and boosts the HER kinetics, thereby notably promoting the intrinsic activity.

Understanding the association between precious metals and trace elements in ore minerals is integral to ore deposit research and exploration. In situ characterization of ore minerals is now at the forefront of this field. The power of in situ element mapping and characterization is the ability to combine geochemistry with mineralogical and broader geological context. Synchrotron radiation (SR) X-ray techniques such as X-ray Fluorescence (XRF) and X-ray Absorption Near Edge Spectroscopy (XANES) are incredibly powerful tools for studying ore systems with applications in exploration, geometallurgy, and remediation. We provide examples of these applications to gold-bearing samples from across the world-class Timmins gold camp in Canada. Analysis of thin sections, billet offcuts, as well as cut rock slabs highlights the versatility of SR-XRF and XANES analysis at multiple stages of deposit investigation and for multiple sample types. SR-XRF mapping of large areas at 20 μm resolution is very effective for quickly identifying and characterizing gold and trace element associations with gold, even in low grade and nuggety samples. Large area mapping is integral to quickly providing key geochemical information within the sample context as well as for improving efficiency and mitigating bias in grain selection for higher resolution analyses. High-resolution SR-XRF mapping and XANES analysis of individual mineral grains are compared to conventional EPMA mapping and reveals micrometer scale associations with trace metals, Au, and As. The characterization of trace element associations with different fluid events and gold mineralization styles is integral to understanding mineralizing systems and developing exploration vectors. Point XRF and XANES identified and characterized the presence and nature of refractory gold in pyrite as well as grain scale variability in As speciation. An early understanding of the distribution and redox state of gold, trace metals, and deleterious elements at the exploration stage has implications for mitigating future geometallurgy and remediation issues. The examples presented highlight the potential for the application of synchrotron studies early in the mine cycle for characterizing gold mineralization in orogenic systems.

Tantalum (Ta) exists in body-centered cubic (α phase), tetragonal (β phase), and face-centered cubic (fcc) crystal structures. The β phase is a metastable structure formed in thin films and is often mixed with the α phase. The fcc phase has only previously been reported as dispersed fine grains embedded in α or β phase. In this study, Ta thin films were deposited on silicon substrates by magnetron sputtering. A mixture of α and β phases was observed in the films when the deposition temperature was lower than 400 °C. The β phase content decreased gradually with the increase in deposition temperature, and completely disappeared at 400 °C. It is interesting that when the deposition temperature reached 500 °C, both α and β phases disappeared, and Ta films became a fcc structure. The structure and the stabilization of the fcc Ta thin films were further investigated using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy, and the results are presented in the present paper. This new finding would open new research and application directions for Ta materials.

Polycyclic aromatic hydrocarbons are hazardous contaminants existing ubiquitously in polluted soil. In this study, using nanocellulose (CNC) fluid as an eco-friendly agent was proposed for the first time in the remediation of phenanthrene (PHE) contaminated soil. The effects of environmental factors on the mobilization of PHE in soil by CNC nanofluid was investigated using factorial analysis. The results showed that temperature and ionic strength had a significant influence on PHE removal, which were associated with the viscosity and zeta potential change in the nanofluid. The analysis based on two-dimensional correlation spectroscopy integrated with FTIR and synchrotron-based XRF imaging revealed that metals and minerals in soil played important roles in PHE detachment. The hydroxyl groups on CNC bonded with Fe-O, Si-O, and Mn-O in soil as time went on, and eventually achieved PHE mobilization through the interruption of PHE/SOM-metal/mineral linkages. The complexation and transport of PHE/SOM-metals/minerals from soil particles to the aqueous phase could be the primary PHE removal mechanism. Besides, the biotoxicity study displayed a detoxification effect of CNC nanofluid on PHE contaminants in soil. This study offers new insight into a cost-effective and biodegradable nanocellulose washing agent, which can be a good alternative to the available site remediation options.

Synchrotron Laue microdiffraction imaging (MDI) is a well-used technique in material science research and environmental research to determine the strain/stress and orientation of quartz and calcite crystallites. However, Laue MDI has unrealized potential to provide spatially resolved mineralogical information for geochemical and contaminated site samples. In this manuscript, three constructed mineral mixtures and two environmental samples were analyzed with Laue MDI to illustrate the strengths, limitations/challenges, and applicability of the technique for environmental research. Mixture 1 (quartz, calcite, and magnetite), mixture 2 (quartz, calcite, magnetite, and clinochlore), and mixture 3 (calcite, hematite, sphalerite, and arupite) were constructed to highlight the potential limitations of the technique. The mixtures illustrate the potential of Laue MDI and X-ray fluorescence imaging for clearly identifying environmentally relevant contaminant and sorbent minerals while demonstrating that minerals sm...

CO2 reduction reaction (CO2RR) is one of the most promising approaches to alleviating greenhouse gas effect and simultaneously producing value-added chemicals and has been widely studied in recent years. To this end, a composite of indium species on CuO (InOx@CuO) was facilely synthesized for CO2RR, and it is found that the selectivity of the target product could be accurately tuned through incorporating post-transition species with Cu-based materials; the desirable Faraday efficiencies of over 90%, with a maximum value of 97.8%, toward CO formation were achieved in a wide potential window from −0.3 to −0.7 V. Moreover, a high CO partial current density of 7.2 mA cm−2 and a long-term stability of 50 h with negligible degradation were obtained over InOx@CuO. More importantly, CO starts to be observed at an ultralow potential of −0.196 V, further confirming the excellence of InOx@CuO for CO2RR toward CO formation. The results demonstrate that the achieved superiority derives from the essential In species on CuO, which not only introduces more active sites, but also better stabilizes the key intermediates, accelerates electron transfer and increases CO2 adsorption.

The fabrication of an efficient and low-cost photocathode still remains a big challenge. We herein report a Ag/CuxO@rGO/Mo photocathode for CO2 conversion. A unique wavelength-dependent performance is found to enhance the formation of the key intermediate groups by exciting photothermal local surface plasmonic resonance (LSPR) using the lights with wavelengths ranging from 550 to 600 nm. CO, H2 and CH4 can be stably produced with dual photoelectrodes using a neutral solution. An unbiased solar-to-gaseous-carbon-fuel efficiency (SGCF) of 0.51 % has been achieved, which sets a record for carbon gas fuel production with binary photoelectrodes. In addition, the CO/H2 ratio could be tuned in the range from 0.65 to 1.84, which makes it possible to fine tune the syngas production. The excellent PEC CO2 reduction capability achieved by the new wavelength-dependent catalytic route may shine some lights for the future design and development of the next-generation PEC materials and devices.