Concentration Of Free Radicals Research Articles

Study on the effect of mixed particle size on coal heat release characteristics

ABSTRACT To study the oxidation characteristics of coal under different conditions of mixed particle sizes, a C80 microcalorimeter and ESR spectrometer were used to study the heat release characteristics and laws of free radical parameter changes for coal samples with different mixed particle sizes. Research indicates that a smaller average particle size in the mixed coal sample results in stronger low-temperature oxidation and greater heat release from coal and a smaller apparent activation energy and initial heat release temperature. The concentration of free radicals in coals increases with decreasing average particle size in the mixed coal samples. When the average particle size in the mixed coal sample increased from 0.09 mm to 0.246 mm, the cumulative heat release of the GJW coal sample and the YHP coal sample decreased by 36.67% and 20.13%, and the free radical concentration decreased by 4.34 × 1017/g and 3.66 × 1017/g. In addition, In the mixed coal samples, the mean particle size mutation value was 0.126, which makes the heat release characteristics of coal at this particle size opposite to the overall trend. Further analysis established the relationship model between the heat of different mixed particle sizes and the free radical concentration of different mixed particle sizes as follows: y = ax3+ bx2+ cx+d.

The Role of the Thioredoxin Detoxification System in Cancer Progression and Resistance.

The intracellular redox homeostasis is a dynamic balancing system between the levels of free radical species and antioxidant enzymes and small molecules at the core of cellular defense mechanisms. The thioredoxin (Trx) system is an important detoxification system regulating the redox milieu. This system is one of the key regulators of cells’ proliferative potential as well, through the reduction of key proteins. Increased oxidative stress characterizes highly proliferative, metabolically hyperactive cancer cells, which are forced to mobilize antioxidant enzymes to balance the increase in free radical concentration and prevent irreversible damage and cell death. Components of the Trx system are involved in high-rate proliferation and activation of pro-survival mechanisms in cancer cells, particularly those facing increased oxidative stress. This review addresses the importance of the targetable redox-regulating Trx system in tumor progression, as well as in detoxification and protection of cancer cells from oxidative stress and drug-induced cytotoxicity. It also discusses the cancer cells’ counteracting mechanisms to the Trx system inhibition and presents several inhibitors of the Trx system as prospective candidates for cytostatics’ adjuvants. This manuscript further emphasizes the importance of developing novel multitarget therapies encompassing the Trx system inhibition to overcome cancer treatment limitations.

Interfacial Reinitiation of Free Radicals Enables the Regeneration of Broken Polymeric Hydrogel Actuators

Interfacial Reinitiation of Free Radicals Enables the Regeneration of Broken Polymeric Hydrogel Actuators

Effect of Solvents on Persistent Free Radical Content in the Absence of Reactions

Effect of Solvents on Persistent Free Radical Content in the Absence of Reactions

Enhanced chlortetracycline removal by iron oxide modified spent coffee grounds biochar and persulfate system

Chlortetracycline (CTC) is a tetracycline derivative antibiotic that has been widely used in the livestock industry for prophylactic and therapeutic purposes. Effective measures should be taken to decrease the environmental risks associated with CTC-rich waste. Biochar produced by biomass waste showed great potential for organic contaminants removal by adsorption and catalytic degradation. This study prepared iron oxide-modified coffee grounds biochar (CGF) at different temperatures for enhanced CTC removal by adsorption and degradation. The main mechanism for CTC removal was found to be electrostatic interaction. In addition, pore diffusion, hydrogen bonds, and π-π bonds also contributed to CTC adsorption. Maximum CTC adsorption capacity was 223.63 mg/g for CGF800 (CGF prepared at 800 °C pyrolysis). The free radical content of CGF600 (CFG prepared at 600 °C pyrolysis) was higher than CGF800, and there were no significant advantages in using biochar prepared at a higher temperature for persulfate activation. The ion mass-to-charge ratio (M/z) is used to describe the ratio of mass to charge of an ion or peak, which can infer compound structure. The structure of CTC degradation products was analyzed by UPLC-MS, and the M/z values were determined as 444, 273, and 154. Thus, pyrolysis of coffee grounds at higher temperatures increased CTC adsorption capacity, and CGF can indirectly assist in CTC degradation by persulfate activation.

Possible Roles of Specific Amino Acids in β-Tubulin Isotypes in the Growth and Maintenance of Neurons: Novel Insights From Cephalopod Mollusks.

Microtubules, are formed of the protein tubulin, which is a heterodimer of α- and β-tubulin subunits. Both α- and β-tubulin exist as numerous isotypes, differing in amino acid sequence and tissue distribution. Among the vertebrate β isotypes, βIII has a very narrow distribution, being found primarily in neurons and in advanced cancers. The places in the amino acid sequence where βIII differs from the other β isotypes are highly conserved in evolution. βIII appears to be highly resistant to reactive oxygen species and it forms highly dynamic microtubules. The first property would be very useful in neurons, which have high concentrations of free radicals, and the high dynamicity would aid neurite outgrowth. The same properties make βIII useful in cancers. Examination of the amino acid sequences indicates a cysteine cluster at positions 124–129 in βIII (CXXCXC). This occurs in all βIII isotypes but not in βI, βII, or βIV. βIII also lacks the easily oxidized C239. Both features could play roles in free radical resistance. Many aggressive tumors over-express βIII. However, a recent study of breast cancer patients showed that many of them mutated their βI, βII, and βIV at particular places to change the residues to those found at the corresponding sites in βIII; these are all sites that are highly conserved in vertebrate βIII. It is possible that these residues are important, not only in the resistance to free radicals, but also in the high dynamicity of βIII. The cephalopod mollusks are well known to be highly intelligent and can remodel their own brains. Interestingly, several cephalopods contain the cysteine cluster as well as up to 7 of the 17 residues that are highly conserved in vertebrate βIII, but are not found in βI, βII, or βIV. In short, it is possible that we are looking at a case of convergent evolution, that a βIII-like isotype may be required for neuronal growth and function and that a structure-function study of the particular residues conserved between vertebrate βIII and cephalopod tubulin isotypes could greatly increase our understanding of the role of the various tubulin isotypes in neuronal growth and function and could aid in the development of novel anti-tumor drugs.

Effect of thermal damage on pore development and oxidation reaction of coal

AbstractWith the coal entering deep mining, the thermal damage to the destruction of the coal body structure, causing the phenomenon of coal spontaneous combustion is more and more common. To better understand the effect of thermal damage on coal spontaneous combustion, the law of thermal damage on pore structure and free radical of coal was studied by automatic specific surface area analyzer and electron spin resonance spectrometer. It was concluded that 225°C was a key point of thermal damage on coal spontaneous combustion. The pore structure analysis indicates that the specific surface area and pore volume of coal decrease with the increase of thermal damage temperature, while the average pore diameter increases gradually. While the specific surface area of Qianyingzi coal is the lowest at 225°C, which is 67.5% of that of raw coal. The average pore size of Zhaotong coal continues to increase by 18.9%. In addition, the pore structure of coal changes greatly in the thermal damage temperature range of 150–225°C, and the connectivity of coal pore is greatly strengthened at this range. The free radical results show that the free radical concentration in thermally damaged coal soars, compared with that in raw coal, and reaches the maximum value at 225°C, indicating that the active groups in coal are greatly active at this temperature. The g factor value declines firstly, then increases, and finally falls. These investigations may serve to reveal the internal mechanism of thermal damage on coal structure and natural oxidation characteristics and provide experimental basis for the prevention and control of coal spontaneous combustion affected by thermal damage.

Interface engineering of ZnO/In2O3 Z-scheme heterojunction with yolk-shell structure for efficient photocatalytic hydrogen evolution

Photocatalytic activities based on charge transfer and separation at interfaces can be effectively promoted by matching chemical Z-scheme heterojunctions and electronic structures. However, the fabrication of morphology-controlled heterojunctions has been a challenge to many researchers. Herein, hollow spheres ZnO/In2O3 was constructed via hydrothermal strategy by fine-tuning the concentration of metal nitrate precursors, and special yolk-shell morphology was generated by the symmetrical Ostwald ripening process. The fabricated Z-Scheme heterojunction exhibited characteristic multi-channel charge transfer properties, which favors the spatial separation of carriers. The ZnO/In2O3 hollow spheres increased the utilization of light source, and the yolk-shell structure increased the interface area and the active sites. Benefiting from the synergistic effect, the ZnO/In2O3 exhibited excellent photocatalytic activities for H2 production, which was comparatively 26.7 times that obtained using ZnO nanoparticles. From calculations based on DFT, the Z-scheme photogenerated charge transfer mechanism was proposed. The proposed mechanism was verified by analyzing the chemical properties (surface) and the •O2− and •OH free radical concentrations before and after the photoreaction. The mechanism presented the ZnO/In2O3 with strong capabilities for H2 production and elucidated the improved photocatalytic performances. This work creates an innovative route for constructing Z-scheme photocatalytic systems with great photocatalytic activities for H2 production.

All-dry free radical polymerization inside nanopores: Ion-milling-enabled coating thickness profiling revealed “necking” phenomena

Conformal coating of nanopores with functional polymer nanolayers is the key to many emerging technologies such as miniature sensors and membranes for advanced molecular separations. While the polymer coatings are often used to introduce functional moieties, their controlled growth under nanoconfinement could serve as a new approach to manipulate the size and shape of coated nanopores, hence, enabling novel functions like molecular separation. However, precise control of coating thickness in the longitudinal direction of a nanopore is limited by the lack of a characterization method to profile coating thickness within the nanoconfined space. Here, we report an experimental approach that combines ion milling (IM) and high-resolution field emission scanning electron microscopy (FESEM) for acquiring an accurate depth profile of ultrathin (∼20 nm or less) coatings synthesized inside nanopores via initiated chemical vapor deposition (iCVD). The enhanced capability of this approach stems from the excellent x–y resolution achieved by FESEM (i.e., 4.9 nm/pixel), robust depth (z) control enabled by IM (step size as small as 100 nm with R2 = 0.992), and the statistical power afforded by high-throughput sampling (i.e., ∼2000 individual pores). With that capability, we were able to determine with unparalleled accuracy and precision the depth profile of coating thickness and iCVD kinetics along 110-nm-diameter nanopores. That allowed us to uncover an unexpected coating depth profile featuring a maximum rate of polymerization at ∼250 nm underneath the top surface, i.e., down the pores, which we termed “necking.” The necking phenomenon deviates considerably from the conventionally assumed monotonous decrease in thickness along the longitudinal direction into a nanopore, as predicted by the diffusion-limited kinetics model of free radical polymerization. An initiator-centric collision model was then developed, which suggests that under the experimental conditions, the confinement imposed by the nanopores may lead to local amplification of the effective free radical concentration at z ≤ 100 nm and attenuation at z ≥ 500 nm, thus contributing to the observed necking phenomenon. The ion-milling-enabled depth profiling of ultrathin coatings inside nanopores, along with the initiator-mediated coating thickness control in the z-direction, may serve to enhance the performance of size-exclusion filtration membranes and even provide more flexible control of nanopore shape in the z dimension.

Biological Effect of Gamma Rays According to Exposure Time on Germination and Plant Growth in Wheat

Gamma rays as a type of ionizing radiation constitute a physical mutagen that induces mutations and could be effectively used in plant breeding. To compare the effects of gamma and ionizing irradiation according to exposure time in common wheat (Keumgang, IT 213100), seeds were exposed to 60Co gamma rays at different dose rates. To evaluate the amount of free radical content, we used electron spin resonance spectroscopy. Significantly more free radicals were generated in the case of long-term compared with short-term gamma-ray exposure at the same dose of radiation. Under short-term exposure, shoot and root lengths were slightly reduced compared with those of the controls, whereas long-term exposure caused severe growth inhibition. The expression of antioxidant-related and DNA-repair-related genes was significantly decreased under long-term gamma-ray exposure. Long-term exposure caused higher radiosensitivity than short-term exposure. The results of this study could help plant breeders select an effective mutagenic induction dose rate in wheat.

Applying NV center-based quantum sensing to study intracellular free radical response upon viral infections

Although viruses are known to modify the free radical concentration in infected cells, the exact location and concentrations of such changes remain unknown. Although this information is important to understand the virus pathogenesis and design better anti-viral drugs or vaccines, obtaining it with the conventional free radical/ROS detection techniques is impossible. Here, we elucidate the utility of diamond magnetometry for studying the free radical response of baby hamster kidney-21 cells upon Semliki Forest virus infection. Specifically, we optically probe the alterations in free radical concentration near infectious viruses via measuring the spin–lattice relaxation (T1) of NV defect ensembles embedded in intracellular nanodiamonds. We performed measurements both at random locations as well as close to the virus entry by conjugating viruses to nanodiamond sensors. We observed alterations of T1, which represent the intracellular free radical concentration during the viral replication process. Moreover, relaxometry is also used to monitor real-time free radical variation during the early infectious process.

Thermal Decomposition of Kerogen in High-Carbon Domanic Rock of the Romashkino Oilfield in Sub- and Supercritical Water

The thermal decomposition of kerogen of the high-carbon Domanic rock from the Romashkino oilfield (Russia) in sub- and supercritical water (SCW) at 320, 374, and 420 °C was studied. The Rock-Eval analysis shows that the isolated kerogen from the native rock with an organic carbon (Corg) content of 55.69% is a high-molecular structure (S2 is 159.38 mg HC/g of rock) with an extremely low content of free hydrocarbons (HC) (S1 is 0.33 mg HC/g rock). The kerogen samples contain predominantly iron-bearing minerals (pyrite, ferrihydrite, marcasite, and iron oxide), which form organomineral complexes with kerogen and are poorly soluble in acids. The subcritical water treatment of Domanic rock at 320 °C (17.0 MPa) does not lead to noticeable changes in the kerogen structure. Intensive kerogen decomposition in SCW at 374 °C (24.6 MPa) and 420 °C (24.4 MPa) is accompanied by the formation of gases, saturated and aromatic HC, as well as solid carbonaceous substances such as carbenes/carboids. According to Fourier-transform infrared (FTIR) spectroscopy, the kerogen decomposition is accompanied by a decrease in the length of its aliphatic fragments and an increase in the degree of their branching, as well as an increase in the content of aromatic carbon in comparison with aliphatic one. The number of hydrogen atoms directly associated with ring aromatic structures also decreases, which leads to an increase in the degree of condensation of the kerogen structure. Almost complete destruction of sulfur-containing bonds in the kerogen structure is observed at 420 °C (24.4 MPa), in contrast to other experiments. Electron paramagnetic resonance (EPR) analysis data indicate the destruction of vanadylporphyrin complexes with the increase in the concentration of free radicals in the kerogen structure under the SCW influence. Distinctive features of the composition and distribution of biogenic, rare-earth, and radioactive trace elements (TE) in the rock and isolated kerogen samples were revealed by inductively coupled plasma–mass spectrometry (ICP–MS). Based on the ratios of H/Cat to O/Cat on the van Krevelen diagram, hydrogen index to Tmax, FTIR spectral parameters (A factor to C factor) of kerogen samples, and the biomarker parameters of saturated and aromatic HC, it was determined that with an increase in the temperature and pressure of SCW, the degree of kerogen maturity increases. Changes in the pore space of the kerogen structure have been established by scanning electron microscopy: the pore size increases at 374 °C (24.6 MPa) and decreases at 420 °C (24.4 MPa) due to the contamination by carbonaceous substances, which affects the oil recovery from Domanic rocks.

Magic angle spinning dynamic nuclear polarization solid-state NMR spectroscopy of γ-irradiated molecular organic solids

In the past 15 years, magic angle spinning (MAS) dynamic nuclear polarization (DNP) has emerged as a method to increase the sensitivity of high-resolution solid-state NMR spectroscopy experiments. Recently, γ-irradiation has been used to generate significant concentrations of homogeneously distributed free radicals in a variety of solids, including quartz, glucose, and cellulose. Both γ-irradiated quartz and glucose previously showed significant MAS DNP enhancements. Here, γ-irradiation is applied to twelve small organic molecules to test the applicability of γ-irradiation as a general method of creating stable free radicals for MAS DNP experiments on organic solids and pharmaceuticals. Radical concentrations in the range of 0.25 ​mM–10 ​mM were observed in irradiated glucose, histidine, malic acid, and malonic acid, and significant 1H DNP enhancements of 32, 130, 19, and 11 were obtained, respectively, as measured by 1H→13C CPMAS experiments. However, concentrations of free radicals below 0.05 ​mM were generally observed in organic molecules containing aromatic rings, preventing sizeable DNP enhancements. DNP sensitivity gains for several of the irradiated compounds exceed that which can be obtained with the relayed DNP approach that uses exogeneous polarizing agent solutions and impregnation procedures. In several cases, significant 1H DNP enhancements were realized at room temperature. This study demonstrates that in many cases γ-irradiation is a viable alternative to addition of stable exogenous radicals for DNP experiments on organic solids.

Proteomic analysis of Fusarium sp. NF01 revealed a multi-level regulatory machinery for lignite biodegradation

Proteomic analysis provides vital bioinformation for revealing the mechanisms of coal biodegradation. Yet, proteomics-based studies of coal biodegradation are generally lacking. We first studied the physio-chemical changes in lignite biodegradation by a previously isolated fungus (Fusarium sp. NF01). The strain was able to degrade lignite showing significant changes in the ultraviolet–visible absorbance, surface structure and a 40.9% increased free radical concentration of residual lignite. Subsequently, isobaric tandem mass tags (TMT) and bioinformatic analysis were used for the quantitative and qualitative analyses of Fusarium sp. NF01 secretome. The expression levels of 62 proteins were significantly altered in the lignite-supplemented medium: 20 proteins were upregulated (fold-change, FC ≥ 2; P-value ≤0.05) and 42 proteins were downregulated (FC ≤ 0.5, P-value ≤0.05). Bioinformatic analysis indicated that Fusarium sp. NF01 acclimatized to the lignite-rich environment by regulating the expression of proteins involved in defense, lignite degradation, detoxification, and cellular metabolism. These findings may help promote sustainable and value-added coal utilization.

EPR Study of Coffee

Six medium and dark roast coffees and its grounds and one non-roast coffee samples in solidstate from the one of coffee shops in Ulaanbaatar city were studied by the EPR spectroscopy.Singlet, low intensity but broad (16-17 Gs) EPR spectrum was registered near the 3400 Gsmagnetic field from the all samples. Free radical concentration was evaluated about 1016 spinwhich can be a measure of antioxidative property.

Simultaneous Pyrolysis of Coal and Biomass in a Drop-Tube-Fixed-Bed Reactor.

Copyrolysis of coal and biomass has been extensively studied to exploit its inherent synergistic effects; however, the different pyrolysis temperature zones of coal and biomass seriously affect the realization of these effects. Therefore, a new copyrolysis method (preheating the coal to a certain temperature and then adding the biomass in a drop-tube–fixed-bed reactor, denoted as M1) was designed herein to achieve “simultaneous” pyrolysis of coal and biomass. The yields of products and the characteristics of M1-produced tar were estimated and compared with those of tar obtained by fixed-bed-reactor (denoted as M2)-based copyrolysis. M1 achieved a higher tar yield and lower water content than M2. The M1-generated tar exhibited a lower free-radical concentration, higher H/C ratio, higher levels of uncondensed aromatic hydrogen, and shorter side-chains than that produced by M2. The temperature of HLBE coal at which the WSs were fed to the reactor in M1, denoted as TF, affects the “simultaneous” pyrolysis. TF values of 300, 400, and 500 °C were studied, and it was found that the tar yield obtained at a TF of 400 °C (the main pyrolysis temperature of coal) is the highest, the water yield is the lowest, and the free-radical concentration of the tar is also the lowest among the investigated samples.

Physical and Chemical Mechanisms of Reactions that Proceed at Extremely High Rates in a Propagating Flame and the Detonation of Gas

The characteristic periods of the reactions in a propagating flame and the detonation of most gases are found to be less than 10−4 and 10−6 s, respectively. The extreme rates and accelerations of reactions responsible for such short times correspond to the law of the dependence of the rate of the combustion reaction on temperature, which is an exponent containing a Boltzmann factor in a positive power index. The kinetics of the processes is determined mainly by a sharp increase in the concentrations of free atoms and radicals as they approach those of the initial reagents. The conclusions of the theory agree with experimental results.

Forced Solid-State Oxidation Studies of Nifedipine-PVP Amorphous Solid Dispersion.

In the present study, the oxidative degradation behavior of nifedipine (NIF) in amorphous solid dispersions (ASDs) prepared with poly(vinyl pyrrolidone) (PVP) with a short (K30) and a long (K90) chain length was investigated. The ASDs were prepared via dry ball-milling and analyzed using Fourier transform infrared (IR) spectroscopy, X-ray scattering, and differential scanning calorimetry. The ASDs were exposed to accelerated thermal-oxidative conditions using a pressurized oxygen headspace (120 °C for 1 day) and high temperatures at atmospheric pressure (60-120 °C for a period of 42 days). Additionally, solution-state oxidative degradation studies showed that pure NIF degrades to a greater extent than in the presence of PVP. Electronic structure calculations were performed to understand the impact of drug-polymer intermolecular interactions on the autoxidation of drugs. While no drug degradation was observed in freshly prepared ASD samples, alkyl free radicals were detected via electron paramagnetic resonance (EPR) spectroscopy. The free radicals were found to be consumed to a greater extent by PVP K30- than PVP K90-based ASDs upon exposure to high oxygen pressures. This was consistent with the greater solid-state oxidative degradation of NIF observed in ASDs with PVP K30 than with PVP K90. As no drug recrystallization occurred during this study period, the lower glass-transition temperature and presumed greater molecular mobility of PVP K30 and its ASD as compared to the PVP K90 system appear to contribute to the greater drug degradation in PVP-K30-based ASDs. The extent and the rate of oxidative degradation were higher in the case of PVP-K30-based ASD as compared to that in PVP-K90-based ASD, and the overall degradation increased with an increase in temperature. IR spectral analysis of drug-polymer interactions supports the electronic calculations of the oxidation process. We infer that, apart from the initial free radical content, the difference in the extent of drug-polymer intermolecular interactions in ASDs and amorphous stabilization during the forced oxidation experiments contribute to the observed differences in the autoxidative reactivity of the drug in ASDs with different PVP chain lengths. Overall, the chemical degradation of NIF in ASDs with two PVP chain lengths obtained from accelerated solid-state oxidation studies was in qualitative agreement with that obtained from long-term (3 years) storage under ambient conditions. The study highlights the ability of accelerated processes to determine the oxidative degradation behavior of polymeric ASDs and suggests that the polymer chain length could factor into chemical as well as physical stability considerations.

Effect of operating conditions and water matrix on the performance of UV combined electrochemical process for treating Chloride-containing solution and its reaction mechanism

The performance of ultraviolet combined electrochemical (EC) process for treating chloride-containing (UV/EC/Cl-) solution was evaluated based on the N, N-Diethyl-m-toluamide (DEET) degradation. The influences of operating conditions and water matrix on the DEET degradation were investigated, and the reaction mechanism of UV/EC/Cl- process was discussed based on the analysis of DEET degradation pathway, the detection of the steady-state concentrations of active free radicals and the analysis of free radicals scavenging. The observed reaction rate constant of DEET degradation in UV/EC/Cl- process (0.093 min−1) is significantly higher than that of UV/Cl2 process (0.036 min−1), and the synergistic effect on the DEET degradation is remarkable in UV/EC/Cl- process. The current and chloride concentration have remarkable impact on the DEET degradation, while the initial pH, reaction temperature, and initial DEET concentration have slight influence on the DEET degradation. The impact of alkalinity on DEET degradation is more significant than that of ammonia, while sulfate and phosphate have slight effect on the DEET degradation. The active points attacked by free radicals on DEET molecule were predicted basing on density functional theory. During the DEET degradation, small molecular products are produced through a series of reactions such as hydrogen abstraction, substitution, dealkylation, and ring-opening. The steady-state concentrations of HO• and Cl• in UV/EC/Cl- process (1.57 × 10-13 M and 2.37 × 10-14 M, respectively) are higher than those of UV/Cl2 process (1.23 × 10-13 M and 1.07 × 10-14 M, respectively), and HO• and Cl• play key roles in the DEET degradation during the UV/EC/Cl- process.

Non-Stacked γ-Fe2O3/C@TiO2 Double-Layer Hollow Nanoparticles for Enhanced Photocatalytic Applications under Visible Light.

Herein, a non-stacked γ-Fe2O3/C@TiO2 double-layer hollow nano photocatalyst has been developed with ultrathin nanosheets-assembled double shells for photodegradation phenol. High catalytic performance was found that the phenol could be completely degraded in 135 min under visible light, due to the moderate band edge position (VB at 0.59 eV and CB at −0.66 eV) of the non-stacked γ-Fe2O3/C@TiO2, which can expand the excitation wavelength range into the visible light region and produce a high concentration of free radicals (such as ·OH, ·O2−, holes). Furthermore, the interior of the hollow composite γ-Fe2O3 is responsible for charge generation, and the carbon matrix facilitates charge transfer to the external TiO2 shell. This overlap improved the selection/utilization efficiency, while the unique non-stacked double-layered structure inhibited initial charge recombination over the photocatalysts. This work provides new approaches for photocatalytic applications with γ-Fe2O3/C-based materials.