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Carbon fiber-based self-supported has excellent catalytic performance and can be further improved by various modifications under the guidance of the regulatory strategies of size, defect, strain, interface effect, and so on.

Understanding the atomic diffusion process of a metal oxide helps with the design of more effective oxygen carriers for chemical looping with oxygen uncoupling (CLOU). Herein we investigated the atomic diffusion process in both slab and bulk CuO with varying oxygen vacancy (VO) under CLOU conditions using density functional theory (DFT) calculations and molecular dynamic (MD) simulation based on the neural network (NN) potential. Although the diffusions of both the Cu and the O atoms are important for the slab model, the O atoms’ outward diffusion to fill surface VOdominates the interlayer diffusion. In contrast, Cu atoms barely diffuse in the bulk model, and the diffusion process is dominated by O atoms through the VO. The MD-estimated chemical diffusion coefficients (10–9–10–13m2/s) and activation barriers (1.14–1.34 eV) of both models are consistent with those experimentally measured values. The diffusion coefficient increases with increasing VO, and the values of the slab model are two orders of magnitude higher than those of the bulk model with a similar VO. These results indicate that the chemical diffusion is dominated by the surface instead of the bulk, and the diffusion in the bulk only becomes important when it becomes the frontier of oxygen uncoupling, i.e., grain boundary between CuO and Cu2O. The majority of diffusion species (O atom or vacancy) and process revealed in this study provide atomic insight into the diffusion in CuO-based materials.

Characterizing the active site structure and understanding the reaction mechanism at the metal/metal oxide interface are crucial for the design and optimization of many catalytic processes. Herein, the structural evolution of MoOx/Ni(111) accompanied by direct deoxygenation of phenol at the interfacial perimeter sites of MoOx/Ni(111) under hydrodeoxygenation conditions has been investigated based on density functional theory (DFT) calculations. The coordinatively unsaturated Mo site with oxygen vacancies (Moov) plays an essential role in the activation of the C–OH bond, with the Ni–MoOxsite being the active site for C–OH bond breakage. The activation barrier for phenol dehydroxylation was reduced from 1.60 eV on Ni(111) to 1.35 eV on Mo3O7/Ni(111), and then to 0.95 eV on Mo3O5/Ni(111), indicating that the lower the oxidation state of the Moovsite, the higher the activity toward the C–OH bond cleavage. Microkinetic parameter analysis showed that the dehydroxylation of phenol is the rate-limiting step. In addition, the reduction of Mo3O7/Ni(111) to Mo3O5/Ni(111) is energetically more favorable than the deoxygenation of phenol at the Moovsite of Mo3O7/Ni(111). In contrast, the Moovsite of Mo3O5/Ni(111) shows high activity for phenol deoxygenation and Mo3O5/Ni(111) cannot be further reduced under the reaction conditions, making the Mo3O5/Ni(111) interfacial sites the dominant active centers for deoxygenation. The nature of the active centers and the mechanism of deoxygenation revealed in this study are helpful for designing Ni-based catalysts for direct deoxygenation of phenolics to aromatics and optimizing the operating conditions.

Molecular structures are commonly depicted in 2D printed forms in scientific documents such as journal papers and patents. However, these 2D depictions are not machine readable. Due to a backlog of decades and an increasing amount of printed literatures, there is a high demand for translating printed depictions into machine-readable formats, which is known as Optical Chemical Structure Recognition (OCSR). Most OCSR systems developed over the last three decades use a rule-based approach, which vectorizes the depiction based on the interpretation of vectors and nodes as bonds and atoms. Here, we present a practical software called MolMiner, which is primarily built using deep neural networks originally developed for semantic segmentation and object detection to recognize atom and bond elements from documents. These recognized elements can be easily connected as a molecular graph with a distance-based construction algorithm. MolMiner gave state-of-the-art performance on four benchmark data sets and a self-collected external data set from scientific papers. As MolMiner performed similarly well in real-world OCSR tasks with a user-friendly interface, it is a useful and valuable tool for daily applications. The free download links of Mac and Windows versions are available at https://github.com/iipharma/pharmamind-molminer.

The field of engineered living materials aims to construct functional materials with desirable properties of natural living systems. A recent study demonstrated the programmed self-assembly of bacterial populations by engineered adhesion. Here we use this strategy to engineer self-healing living materials with versatile functions. Bacteria displaying outer membrane-anchored nanobody–antigen pairs are cultured separately and, when mixed, adhere to each other to enable processing into functional materials, which we term living assembled material by bacterial adhesion (LAMBA). LAMBA is programmable and can be functionalized with extracellular moieties up to 545 amino acids. Notably, the adhesion between nanobody–antigen pairs in LAMBA leads to fast recovery under stretching or bending. By exploiting this feature, we fabricated wearable LAMBA sensors that can detect bioelectrical or biomechanical signals. Our work establishes a scalable approach to produce genetically editable and self-healable living functional materials that can be applied in biomanufacturing, bioremediation and soft bioelectronics assembly.

Household energy-related CO2emissions (HCEs) are significant sources of increased CO2emissions in China. Understanding the distribution and evolution of HCEs in different geographical areas is favorable for low-carbon development and climate change mitigation. However, there has been little research on this topic, especially in geographical demarcation areas. Here, using prefecture-level cities traversed by the Qinling mountains–Huaihe river line (Qinling–Huaihe line) as the study areas, we quantified the HCEs based on statistical and nighttime light data from 2000 to 2017. We revealed the evolutionary trends and structural changes of HCEs and looked into how HCEs are impacted by social and natural factors. The results show that northern regions tend to have higher HCEs than southern regions at similar longitudes, and this trend remains stable for a long period of time due to the long-term and stable living habits and consumption behaviors with regional characteristics. Cities with the highest HCEs are located in the central region, followed by the eastern region, and the lowest in the western. The longitude evolution of HCEs is centered on medium-emission cities, which moved eastward from 111–117°E and turned major aggregation of medium-high emissions up to 2015 by the economic driving force. The distribution of fixed crosses is inconsistent with the HCEs and energy structure, demonstrating the counteracting effects of energy structure optimization on HCEs are far less than the promoting effects of energy demand. Although HCEs increased as GDP and population increased, these effects were partially offset when adjusting for urban layout and human activity density. This paper provides a reference for reducing CO2emissions in the geographical demarcation areas and puts forward policy suggestions.

Meniscal injuries have poor intrinsic healing capability and are associated with the development of osteoarthritis. Decellularized meniscus extracellular matrix (mECM) has been suggested to be efficacious for the repair of meniscus defect. However, main efforts to date have been focused on the concentration, crosslinking density and anatomical region dependence of the mECM hydrogels on regulation of proliferation and differentiation of adult mesenchymal stem cells (MSCs) in vitro2D or 3D culture. A systematic investigation and understanding of the effect of mECM on encapsulated MSCs response and integrative meniscus repair by in vivorat subcutaneous implantation and orthotopic meniscus injury model will be highly valuable to explore its potential for clinical translation. In this study, we investigated the in situdelivery of rat BMSCs in an injectable mECM hydrogel to a meniscal defect in a SD rat model. Decellularized mECM retained essential proteoglycans and collagens, and significantly upregulated expression of fibrochondrogenic markers by BMSCs versus collagen hydrogel alone in vitro3D cell culture. When applied to an orthotopic model of meniscal injury in SD rat, mECM is superior than collagen I scaffold in reduction of osteophyte formation and prevention of joint space narrowing and osteoarthritis development as evidenced by histology and micro-CT analysis. Taken together, these results indicate mECM hydrogel is a highly promising carrier to deliver MSCs for long-term repair of meniscus tissue, while preventing the development of osteoarthritis.

CeO2–UiO octahedron catalysts derived from cerium-based metal–organic frameworks Ce–UiO-66 were synthesized for vapor-phase ketonization of propionic acid. Characterizations showed the CeO2–UiO octahedron is assembled from nanosized CeO2crystallites with mesopores. XPS and Raman results indicated that more oxygen vacancies are formed in CeO2–UiO-450 catalyst than in CeO2–P prepared by a precipitation method. Intrinsic ketonization rates on CeO2–UiO-450 are improved relative to CeO2–P. At 350 °C, the turnover frequency based on acid–base pair on CeO2–UiO-450 (7.45 s–1) is 1.38 times higher than that on CeO2–P (5.41 s–1). Consistently, the activation energy is lowered from 130.5 kJ/mol for CeO2–P to 109.0 kJ/mol for CeO2–UiO-450. Infrared spectroscopy results showed that monodentate carboxylate is the active adsorption configuration, and its consumption is much faster on CeO2–UiO-450 than on CeO2–P. A linear correlation between the concentration of oxygen vacancy and intrinsic ketonization rate is found, indicating that the oxygen vacancy promotes ketonization on CeO2.

Density functional theory calculations are employed to elucidate the mechanism of ammonia synthesis on the nitridated Mo2N(111) surfaces. An ensemble consisting of four Mo atoms arranged in roughly a rhombic structure (Mo4) was found highly active for N2adsorption and activation, with an activation barrier of 0.58 eV to break the N–N bond. However, subsequent hydrogenation of the adsorbed NHx(x= 0, 1, and 2) species on the Mo4site becomes rate-limiting as the activation barriers increase up to 1.47 eV. Nitridation in close proximity to the Mo4site can significantly improve the activity for NHxhydrogenation, and the activity is more sensitive to the location rather than the overall coverage of N. The Mo4site modified anisotropically by surface N adatoms next to the site maintains its high reactivity toward dissociative N2adsorption while reduces the activation barriers for NHxhydrogenation. Bonding with the N adatoms distorts the Mo4ensembles geometrically and modifies the active sites electronically. Microkinetic analysis based on the energetic results indicates that the Mo4ensembles modified with N adatoms at the corner site formed in intermediate N coverages are highly active toward ammonia formation. The present study demonstrates the importance of the local structure of the active site for catalytic ammonia synthesis and is helpful to the design of novel active ammonia synthesis catalysts and the selection of optimal operating conditions.

Because mucosal sites are the entry ports of pathogens, immunization viamucosal routes can extremely enhance the immunity. To elevate the potential of N-2-hydroxypropyl trimethylammonium chloride chitosan (N-2-HACC) and N,O-carboxymethyl chitosan (CMC) nanoparticles as a mucosal immune delivery carrier for DNA vaccines, we prepared the NDV F gene plasmid DNA with C3d6 molecular adjuvant (pVAX I-F(o)-C3d6) encapsulated in the N-2-HACC-CMC nanoparticles (N-2-HACC-CMC/pFDNA-C3d6 NPs). The N-2-HACC-CMC/pFDNA-C3d6 NPs had regular spherical morphology and low toxicity with a mean diameter of 309.7 ± 6.52 nm, zeta potential of 49.9 ± 4.93 mV, encapsulation efficiency of 92.27 ± 1.48%, and loading capacity of 50.75 ± 1.35%. The N-2-HACC-CMC had high stability and safety. The pVAX I-F(o)-C3d6 could be sustainably released from the N-2-HACC-CMC/pFDNA-C3d6 NPs after an initial burst release. Immunization intranasally of chickens with N-2-HACC-CMC/pFDNA-C3d6 NPs not only produced higher anti-NDV IgG and sIgA antibody than chickens in other groups did, but also significantly stimulated lymphocyte proliferation and triggered higher the IL-2, IL-4, and IFN-γ levels. These findings indicated that the N-2-HACC-CMC could be used as an efficient delivery carrier for the mucosal immunity of Newcastle disease virus DNA vaccine. The work laid a basis for the quaternized chitosan nanoparticles as efficient mucosal immunity delivery carrier for DNA vaccines and had immense application promise and potential for vaccines and drugs.

The conversion of C2–4carboxylic (acetic, propionic, and n-butyric) acids on HZSM-5 was studied at 350 °C. The reaction proceeds through ketonization (to acetone, 3-pentanone, and 4-heptanone, respectively), aldol condensation, and tertiary reactions to aromatics-rich hydrocarbons. The product distribution is influenced by the carbon chain length of carboxylic acids due to the shape selectivity of ZSM-5. The turnover frequency (TOF) of ketonization of carboxylic acids decreases while the TOF of aldol condensation of corresponding ketones increases with increasing carbon chain length. Langmuir–Hinshelwood mechanism analysis shows that the true activation enthalpy of both ketonization and aldol condensation increases with increasing carbon chain length, due to the increased steric hindrance for the formation of a C–C bond. However, the true Gibbs free activation energy increases for ketonization but decreases for aldol condensation with increasing chain length, due to a greater contribution of activation entropy of aldol condensation than that of ketonization.

Ammonia can be used to produce carbon-free hydrogen for fuel cells and is considered as a key player in a noncarbon economy. In the present study, we investigated ammonia decomposition on Mo2N(100) and (111) surfaces using density functional theory calculations. The stepwise dissociation of ammonia over the surface Mo atom on Mo2N(100) has activation barriers >1.0 eV for all three N–H bonds. In contrast, the activation barriers for dissociating the first and second N–H bond in 3-fold Mo sites on the (111) surface are only 0.64 and 0.22 eV, respectively, whereas the activation barrier for breaking the last N–H bond is 1.12 eV. Coupling of NHxspecies with intrinsic surface N atoms does not always promote N–H bond activation but the formation of NlatNHxspecies needs to overcome a high activation barrier. Consequently, N–N coupling is not expected to have significant contributions to overall ammonia dissociation. Our results also showed that recombinative desorption of N atoms involves the formation of highly activated meta-stable dinitrogen species and its subsequent desorption as the N2molecule. The overall ammonia decomposition is limited by this recombinative desorption process, with an overall energy cost of ∼2.61 eV on Mo2N(100) and ∼1.29 eV on Mo2N(111). On both surfaces, the intrinsic surface N atoms of the nitride actively participate in the formation of desorbed nitrogen, making the process follow a Mars–van Krevelen mechanism.

Ketonization of biomass-derived propionic acid was investigated at 270–350 °C over CexZr1–xO2mixed oxides with varying Ce/Zr ratios. The acidity of CexZr1–xO2increases as Zr content is increased. The density of the strong base sites is reduced with increasing Zr content, while the density of the medium-strength base sites is maximized on Ce0.5Zr0.5O2. Diffuse reflectance infrared spectroscopy of propionic acid adsorption indicated that increasing Zr content in CexZr1–xO2favors monodentate adsorption over bidentate adsorption. The reaction rate varies with the composition of CexZr1–xO2. The intrinsic reaction rate can be correlated with the medium-strength acid/base ratio. The rate maximizes at a medium-strength acid/base ratio of ∼1.07 on Ce0.1Zr0.9O2. This value is close to 1, indicating that the balanced medium-strength acid–base sites play a crucial role in the ketonization. The balanced acid–base property influences propionic acid adsorption, enolate formation, and C–C coupling and therefore affects the ketonization rate.

Developing highly active and stable nonprecious metal catalysts for electrochemical reactions is desirable but remains a great challenge. Herein, we report a novel metal-ion adsorption-pyrolysis strategy for the controllable zeolitic imidazolate framework-8 derived synthesis of individual high-quality N-doped carbon nanotubes embedded with well-dispersed nonprecious metal nanoparticles, which exhibit superior electrocatalytic activity and stability for electrochemical CO2reduction reaction, oxygen reduction reaction, and oxygen evolution reaction. Experimental analysis and density functional theory calculations indicate that the remarkable electrocatalytic activities are mainly attributed to the interface effects for the efficient electron transfer from metal nanoparticles to the N-doped carbon shell, as well as the large specific areas, unique tube structures, appropriate doping, high graphitization degree, and robust frameworks. The high reaction stability is attributed to the multiwalled graphitic carbon shells efficiently preventing metal nanoparticles from aggregation, corrosion, and oxidation. This novel synthetic strategy presents a facile universality for synthesizing N-doped carbon nanotube structures and will provide a guideline for developing low-cost, highly active, and stable electrocatalytic materials for sustainable energy conversion.

The production of acetone through ketonization of acetic acid is both energy intensive and environmentally detrimental, as it emits equimolecular CO2. Herein, a novel approach for acetone production from CO2and CH4was proposed through consecutive C–C coupling based on an extensive density functional theory computational study. To realize the consecutive C–C coupling, CeO2-based catalyst doped with Zn site ensemble was constructed. Direct coupling of CH3* with the acetate species, formed from C–C coupling of CO2and stabilized CH3*, could be achieved to produce acetone. The results show that carbon chain growth is possible on the active site ensembles constructed on a CeO2-based catalyst. The coupling of the acetate species with the methyl moiety follows a nucleophilic addition mechanism and has apparent activation energies of 0.25 and 0.14 eV on Ovac(oxygen vacancy) and neutral surfaces, respectively. This process could potentially replace the traditional acetone production technology based on ketonization of acetic acid.

Electrochemical reduction of CO2to produce useful fuels and chemicals is one of the attractive means to reuse CO2. Herein, we constructed a (TiO2)3/Ag(110) model electrocatalyst and examined CO2reduction pathways. Our results show that the interface between oxide and supporting Ag provides the active sites for CO2adsorption and activation. These active sites enable the electron transfer to the adsorbed CO2. In this setup, Ag acts as an electron donor, partially reducing the supported (TiO2)3and supplies the needed electrons to the adsorbed CO2. Once CO2* is formed at the interface, the subsequent hydrogenation steps take place sequentially. Our results further indicate that the dominating pathway to produce CH3OH is via the H2COOH* intermediate following the formation of HCOO*. The formation of H2COOH* with a free energy of 0.47 eV is the potential-limiting step. Furthermore, protonating H2COOH* followed by dehydration to CH3O* and hydrogenation of CH3O* leads to CH4formation. The COOH* pathway may converge to the same H2COOH* intermediate instead of forming CO*. These results demonstrated the benefit of metal supported metal oxides as electrocatalysts to produce CH3OH or CH4from electrochemical reduction of CO2.

A combined experimental and density functional theory computational study was performed to understand the reaction mechanism of hydrodeoxygenation of phenol on the Pt(111) surface. Partial hydrogenation of phenyl ring reduces the barrier of deoxygenation. The intermediate formed by adding 5 H atoms to the phenyl ring and with α-C adsorption on Pt is identified as the key intermediate responsible for the formation of different products with mild barriers: deprotonating the hydroxyl to cyclohexanone at 0.38 eV, hydrogenation at α-C to cyclohexanol at 0.56 eV, and deoxygenation at 0.76 eV followed by dehydrogenation to benzene. Microkinetic parameter analysis indicates that the hydrogenation steps are fast and reversible while deoxygenation steps are slow and almost irreversible, which is consistent with the experimental observation that hydrogenation products are the major primary products at low conversions while deoxygenation product dominates at high conversions, at 523 K and ambient H2pressure. H2pressure plays an essential role on surface coverage of H and available adsorption sites, modulating the competition between hydrogenation and deoxygenation reactions and, thereby, the product distributions.

Efficient Ni/(S,S)-Ph-BPE-catalyzed asymmetric hydrogenation of α-substituted α,β-unsaturated phosphine oxides/phosphonates/phosphoric acids has been successfully developed, and a wide range of chiral α-substituted phosphines hydrogenation products were obtained in generally high yields with excellent enantioselective control (92%–99% yields, 84%−>99% ee). This method features a cheap transition metal nickel catalytic system, high functional group tolerance, wide substrate scope generality, and excellent enantioselectivity. A plausible catalytic cycle was proposed for this asymmetric hydrogenation according to the results of deuterium-labeling experiments.

Hepatocellular carcinoma (HCC) is a prevalent cancer in China, with chronic hepatitis B (CHB) and liver cirrhosis (LC) being high-risk factors for developing HCC. Here, we determined the serum proteomes (762 proteins) of 125 healthy controls and Hepatitis B virus-infected CHB, LC, and HCC patients and constructed the first cancerous trajectory of liver diseases. The results not only reveal that the majority of altered biological processes were involved in the hallmarks of cancer (inflammation, metastasis, metabolism, vasculature, coagulation), but also identify potential therapeutic targets in cancerous pathways (i.e., IL17 signaling pathway). Notably, the biomarker panels for detecting HCC in CHB and LC high-risk populations were further developed using machine learning in two cohorts comprised of 200 samples (discovery cohort=125, validation cohort=75). The protein signatures significantly improved the area under the receiver operating characteristic curve (AUC) of HCC (CHB discovery and validation cohort = 0.953 and 0.891, respectively; LC discovery and validation cohort = 0.966 and 0.818, respectively) compared to using the traditional biomarker, alpha-fetoprotein (AFP), alone. Finally, selected biomarkers were validated with parallel reaction monitoring (PRM) mass spectrometry in an additional cohort (n=120). Altogether, our results provide fundamental insights into the continuous changes of cancer biology processes in liver diseases and identify candidate protein targets for early detection and intervention.

The role of oxygen species in the product distribution of oxidative carbonylation of phenol was investigated using metal doped cryptomelane-type manganese oxide octahedral molecular sieves M-OMS-2 (M = Pb, Cr, Ce, Zn) as catalysts supports. The oxygen species of Pd/M-OMS-2 catalysts were characterized by H2-TPR and X-ray photoelectron spectra techniques. The results show that the Pd/Pb-OMS-2 catalyst calcined at 300 °C exhibits lower onset reduction temperature and more active OH−groups compared with the other catalysts, so the best diphenyl carbonate (DPC) yield is obtained. When Pb-OMS-2 was used as a support, a vast majority of by-product was 4-bromophenol, and a small amount of 3-phenoxyphenol and biphenyldiol yielded. However, for the Pd/Cr-OMS-2, Pd/Ce-OMS-2 and Pd/Zn-OMS-2 catalysts, the decreased amount of 4-bromophenol was observed while 3-phenoxyphenol and biphenyldiol yielded remarkably. It is deduced that active OH−groups not only improve the DPC yield, but also promote the formation of 4-bromophenol and deep oxidation of phenol.

Electrochemical reduction of CO2has the benefit of turning greenhouse gas emissions into useful resources. We performed a comparative study of the electrochemical reduction of CO2on stepped Pb(211) and Sn(112) surfaces based on the results of density functional theory slab calculations. We mapped out the potential energy profiles for electrochemical reduction of CO2to formate and other possible products on both surfaces. Our results show that the first step is the formation of the adsorbed formate (HCOO*) species through an Eley-Rideal mechanism. The formate species can be reduced to HCOO−through a one-electron reduction in basic solution, which produces formic acid as the predominant product. The respective potentials of forming HCOO* are predicted to be −0.72 and −0.58 V on Pb and Sn. Higher overpotentials make other reaction pathways accessible, leading to different products. On Sn(112), CO and CH4can be generated at −0.65 V following formate formation. In contrast, the limiting potential to access alternative reaction channels on Pb(211) is −1.33 V, significantly higher than that of Sn.

Multi-pitch analysis of concurrent sound sources is an important but challenging problem. It requires estimating pitch values of all harmonic sources in individual frames and streaming the pitch estimates into trajectories, each of which corresponds to a source. We address the streaming problem for monophonic sound sources. We take the original audio, plus frame-level pitch estimates from any multi-pitch estimation algorithm as inputs, and output a pitch trajectory for each source. Our approach does not require pre-training of source models from isolated recordings. Instead, it casts the problem as a constrained clustering problem, where each cluster corresponds to a source. The clustering objective is to minimize the timbre inconsistency within each cluster. We explore different timbre features for music and speech. For music, harmonic structure and a newly proposed feature called uniform discrete cepstrum (UDC) are found effective; while for speech, MFCC and UDC works well. We also show that timbre-consistency is insufficient for effective streaming. Constraints are imposed on pairs of pitch estimates according to their time-frequency relationships. We propose a new constrained clustering algorithm that satisfies as many constraints as possible while optimizing the clustering objective. We compare the proposed approach with other state-of-the-art supervised and unsupervised multi-pitch streaming approaches that are specifically designed for music or speech. Better or comparable results are shown.

A general approach has been developed to synthesize high-quality Cu−In−S based multicomponent solid-solution nanocrystals (NCs) of Zn2x(CuIn)1−xS2, (CuIn)1−xCd2xS2, and (ZnS)x(CuInS2)y(CdS)zat relatively low temperature. This was achieved in a noncoordinating solvent system (toluene) by a simple solvothermal process using metal diethyldithiocarbamate complexes as the precursors. The composition, crystalline structure, size, and bang gap of the NCs could be readily tuned by the precursors used and synthesis conditions. This work provides useful understanding for the synthesis of solid-solution NCs that are of interest for photocatalyst, solar cell, and other applications.

Photocatalytic CO2reduction is a promising route to simultaneously address two critical issues related to the energy and environment. Herein, a direct Z-scheme photocatalytic system, Ti3+defective TiO2/CdS nanoflowers, was fabricated to enhance the production of C1–C3 products from CO2reduction. First, nanoflower-like TiO2(NF-TiO2) is prepared using a TiB2precursor to build in Ti3+defects. Then, the NF-TiO2/CdS heterojunctions are constructed viathe sulfurization of TiO2/Cd-MOF. Importantly, the optimal heterojunction photocatalyst NF-TiO2/CdS0.6exhibits a highly promoted CO2reduction activity not only for CO and CH4but also for C2–C3 hydrocarbons. The cumulative yields of CO and CH4are 1007.0 μmol/g and 83.5 μmol/g (2.5 h), respectively, and a yield of 55.3 μmol/g (2.5 h) of C2–C3 hydrocarbons is obtained. This enhanced yield of C1–C3 products is attributed to the synergistic effects of abundant Ti3+defects that increase adsorption and activation of CO2, the large surface area that provides sufficient active sites, and a direct Z-scheme heterojunction with a good intimate contact interface that effectively separates charge carriers and accumulates electrons with strong reducibility. Moreover, the photoluminescence analysis of hydroxyl radicals was conducted to provide evidence for the direct Z-scheme mechanism. This work provides a facile method for the construction of a TiO2-based direct Z-scheme photocatalytic system for improving photocatalytic performance toward CO2reduction.

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