A crystalline carbon nitride-based separator for high-performance lithium metal batteries.

Lithium metal anodes with ultrahigh theoretical capacities are very attractive for assembling high-performance batteries. However, uncontrolled Li dendrite growth strongly retards their practical applications. Different from conventional separator modification strategies that are always focused on functional group tuning or mechanical barrier construction, herein, we propose a crystallinity engineering-related tactic by using the highly crystalline carbon nitride as the separator interlayer to suppress dendrite growth. Interestingly, the presence of Cl- intercalation and high-content pyrrolic-N from molten salt treatment along with highly crystalline structure enhanced the interactions of carbon nitride with Li+ and homogenized lithium flux for uniform deposition, as supported by both experimental and theoretical evidences. The Li-Li cell with the modified separator therefore delivered ultrahigh stability even after 3,000 h with dendrite-free cycled electrodes. Meanwhile, the assembled Li-LiFePO4 full-cell also presented high-capacity retention. This work opens up opportunities for design of functional separators through crystallinity engineering and broadens the use of C3N4 for advanced batteries.

Cognitive behavior therapy for depression in people with epilepsy: A systematic review and meta-analysis.

BACKGROUND: Cognitive behavioral therapy (CBT) is the recommended treatment for depression in patients with epilepsy (PWE). However, there are no studies that calculate the effect size of CBT on depression and quality of life (QoL) in PWE. METHODS: We searched seven electronic databases (PubMed, Web of Science, Embase, Cochrane Library, Clinical Trials, Ovid Medline, and PsycINFO). We included 13 studies examining CBT for depression in PWE and calculated its effect size. RESULTS: A total of 13 studies met the criteria. After treatment, CBT improves depression in PWE (g = 0.36, 95%CI: 0.18 to 0.54, I2 = 50%), and the efficacy maintains during follow-up (g = 0.47, 95%CI: 0.04 to 0.89, I2 = 80%). Subgroup analysis has shown that individual CBT (g = 0.47, 95%CI: 0.20 to 0.73, I2 = 0%) had a greater effect size than group CBT (g = 0.30, 95%CI: 0.07 to 0.53, I2 = 62%) in the treatment of depression. Likewise, CBT has a positive effect on the QoL improvement of PWE (g = 0.34, 95%CI: 0.11 to 0.57, I2 = 64%). In controlling seizures, CBT did not differ from the control group (g = -0.06, 95%CI: -0.32 to 0.19, I2 = 0%). CONCLUSIONS: Cognitive behavioral therapy interventions were effective in improving depression and QoL in PWE, but not effective in controlling seizures. The efficacy of CBT interventions targeting seizure control seems to be uncertain.

Clarifying the mechanism of apigenin against blood-brain barrier disruption in ischemic stroke using systems pharmacology.

Currently, recombinant tissue plasminogen activator (rtPA) is an effective therapy for ischemic stroke (IS). However, blood-brain barrier (BBB) disruption is a serious side effect of rtPA therapy and may lead to patients' death. The natural polyphenol apigenin has a good therapeutic effect on IS. Apigenin has potential BBB protection, but the mechanism by which it protects the BBB integrity is not clear. In this study, we used network pharmacology, bioinformatics, molecular docking and molecular dynamics simulation to reveal the mechanisms by which apigenin protects the BBB. Among the 146 targets of apigenin for the treatment of IS, 20 proteins were identified as core targets (e.g., MMP-9, TLR4, STAT3). Apigenin protects BBB integrity by inhibiting the activity of MMPs through anti-inflammation and anti-oxidative stress. These mechanisms included JAK/STAT, the toll-like receptor signaling pathway, and Nitrogen metabolism signaling pathways. The findings of this study contribute to a more comprehensive understanding of the mechanism of apigenin in the treatment of BBB disruption and provide ideas for the development of drugs to treat IS.

Synergistic Tuning of the Electronic Structure of Mo2C by P and Ni Codoping for Optimizing Electrocatalytic Hydrogen Evolution.

Developing earth-abundant and highly efficient nonprecious metal catalysts for hydrogen evolution reaction (HER) is critical for the storage and conversion of renewable energy sources. Molybdenum carbide (Mo2C) has been extensively investigated as one of the most promising nonprecious electrocatalysts for boosting HER because of its low cost, high electrical conductivity, good chemical structure, and similar electronic structure to that of Pt. However, Mo2C always exhibits the negative hydrogen-binding energy, which can largely prevent adsorbed H desorption during the HER process. Herein, we report P- and Ni-dual-doped Mo2C in porous nitrogen-doped carbon (P/Ni-Mo2C) as an electrocatalyst for the HER, exhibiting excellent activity and durability with a low overpotential of 165 mV at 10 mA cm-2 in alkaline electrolyte. Density functional theory (DFT) calculations proved that P and Ni acted as the anion and cation, respectively, to synergistically tune the electronic properties of Mo2C to decrease the negative hydrogen-binding energy, endowing the catalyst with excellent catalytic performance for the HER.

Construction of prognostic risk prediction model based on high-throughput sequencing expression profile data in childhood acute myeloid leukemia.

This study aimed to identify critical prognostic molecular markers in Childhood acute myeloid leukemia (AML) and construct nomogram-based model for prognostic prediction. The RNA-sequencing profiles and corresponding clinical information were downloaded from TCGA database. Differential expressed genes (DEG) were screened using limma package, subsequently following by GO and KEGG pathway analysis. Univariate and multivariate cox regression analysis were performed to screen critical DEGs. Nomogram-based prediction model were constructed to identify clinical factors with independent prognostic values, and the accuracy of this model was validated. A total of 214 DEGs were identified from relapse AML samples compared with non-relapse samples. These DEGs were mainly involved in twenty GO terms and three signaling pathways, such as chromatin assembly or disassembly, cytokine-cytokine receptor interaction, and JAK-STAT signaling pathway. Among these genes, Univariate and multivariate cox regression analysis results showed that relapse and risk score were significantly correlated with survival outcomes. Finally, the accuracy ability of nomogram-based prediction model was validated. These six DEGs (ABCA5, CYP7A1, HERC5, etc.) play major roles in AMLs progression. Our nomogram-based prognostic predictive model might be an effective method to estimate survival probability of AML patients with different risk status.

Effects of Ti Doping on Hematite Photoanodes: More Surface States.

Ti doped hematite photoanodes have been intensively investigated due to their excellent activity for photoelectrochemical water oxidation. However, little attention has been paid to the doping effect on the photocurrent onset potential of hematite and the underlying mechanism. In this paper, Ti doped hematite nanorod arrays were successfully prepared through a facile treatment of hematite with TiCl3 solution. The photocurrent of the Ti doped hematite photoanode increases by three times, and its onset potential shifts more positively as compared with that of the undoped one. Electrochemical analyses were employed to unravel the mechanism of anodic shift of the onset potential. Cyclic voltammograms and electrochemical impedance spectra confirmed that more surface states were formed in Ti doped hematite than the undoped one. As a result, lower activity towards oxygen evolution reaction (OER) and increased electron-hole recombination after light on/off in low potential region were observed in Ti doped hematite. It is concluded that these doping induced surface states may be a hindrance to charge transfer and the onset potential of Ti doped hematite shifts anodically.

Giant Hollow Heterometallic Polyoxoniobates with Sodalite-Type Lanthanide-Tungsten-Oxide Cages: Discrete Nanoclusters and Extended Frameworks.

The first series of niobium-tungsten-lanthanide (Nb-W-Ln) heterometallic polyoxometalates {Ln12 W12 O36 (H2 O)24 (Nb6 O19 )12 } (Ln=Y, La, Sm, Eu, Yb) have been obtained, which are comprised of giant cluster-in-cluster-like ({Ln12 W12 }-in-{Nb72 }) structures built from 12 hexaniobate {Nb6 O19 } clusters gathered together by a rare 24-nuclearity sodalite-type heterometal-oxide cage {Ln12 W12 O36 (H2 O)24 }. The Nb-W-Ln clusters present the largest multi-metal polyoxoniobates and a series of rare high-nuclearity 4d-5d-4f multicomponent clusters. Furthermore, the giant Nb-W-Ln clusters may be isolated as discrete inorganic alkali salts and can be used as building blocks to form high-dimensional inorganic-organic hybrid frameworks.

Development of hybrid-type modified chitosan derivative nanoparticles for the intracellular delivery of midkine-siRNA in hepatocellular carcinoma cells.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Most of the patients with HCC lose the surgical opportunity at the time of diagnosis. Some novel therapeutic modalities, like gene therapy, are promising for the treatment of HCC. However, the success of gene therapy depends on two aspects: efficient gene materials and gene delivery vectors. The present study was to develop new chitosan-based nanoparticles for a midkine-siRNA (anti-HCC gene drug) delivery. METHODS: The novel gene delivery vector (MixNCH) was synthesized by hybrid-type modification of chitosan with 2-chloroethylamine hydrochloride and N, N-dimethyl-2-chloroethylamine hydrochloride. The chemical structure of MixNCH was characterized by FT-IR and 1HNMR. The cytotoxicity of MixNCH was determined by MTS assay. The gene condensation ability and size, zeta potential and morphology of MixNCH/MK-siRNA nanoparticles were measured. The in vitro transfection and gene knockdown efficiency of midkine by MixNCH/MK-siRNA nanoparticles was detected by qRT-PCR and Western blotting. Gene knockdown effect at the molecule level on the proliferation of HepG2 in vitro was determined by MTS assay. RESULTS: MixNCH was successfully acquired by aminoalkylation modification of chitosan. The MixNCH could condense MK-siRNA well above the weight ratio of 3. The average size of MixNCH/MK-siRNA nanoparticles was 100-200 nm, and the surface charge was about +5 mV. Morphologically, MixNCH/MK-siRNA nanoparticles were in regular spherical shape with no aggregation. Regarding to the in vitro transfection of nanoparticles, the MixNCH/MK-siRNA nanoparticles reduced MK mRNA level to 14.03%+/-4.03%, which were comparable to Biotrans (8.94%+/-3.77%). MixNCH/MK-siRNA effectively inhibited the proliferation of HepG2 in vitro. CONCLUSION: MixNCH/MK-siRNA nanoparticles could be effective for the treatment of hepatocellular carcinoma.

Efficacy and safety of auricular therapy in the treatment of post-stroke constipation: A protocol for systematic review and meta-analysis.

BACKGROUND: Constipation is one of the common gastrointestinal complications after stroke. It not only aggravates the condition of stroke, but also brings huge medical burden to patients, and has a negative impact on the quality of life of patients. Auricular therapy, as a part of Chinese traditional acupuncture and moxibustion, has been found to be effective in the clinical treatment of constipation. However, no systematic review has investigated the efficacy and safety of auricular therapy in the treatment of post-stroke constipation. Therefore, the aim of this systematic review is to assess the effectiveness and safety of auricular therapy for post-stroke constipation. METHODS AND ANALYSIS: Eight electronic databases including PubMed, Cochrane Library/Cochrane Central Register of Controlled Trials, Web of Science, Embase, China National Knowledge Internet, Chinese Biomedical Literature Database, Wanfang, and VIP databases, will be searched for relevant studies published from inception to February 2023. Two reviewers will independently conduct research selection, data extraction, and evaluation of research quality. Only randomized controlled trials (RCTs) that assess the efficacy and safety of auricular therapy for the treatment of post-stroke constipation will be included in this study. We will use the Cochrane risk of bias assessment tool to evaluate the methodological qualities (including bias risk). If possible, a meta-analysis will be performed after screening. RESULTS: This study may provide high-quality evidence for the efficacy and safety of auricular therapy in treating post-stroke constipation. CONCLUSION: The conclusions of our study will provide an evidence to judge whether auricular therapy is an effective and safe intervention for patients with post-stroke constipation. ETHICS AND DISSEMINATION: Ethical approval is not required, as this study was based on a review of published research. This review will be published in a peer-reviewed journal and disseminated electronically and in print. TRIAL REGISTRATION: Registration number: PROSPERO CRD42023402242.

Coupling Reliable Interfacial Carrier Migration Channels with Visible-Light Response Antennas in ZnO-Based Heterostructure for Ameliorated Photocatalytic Hydrogen Generation.

Engineering targeted and reliable charge transfer pathways in multiphase photocatalysts remains a challenge. Herein, we conceptualize the Cd@CdS-ZnO/reduced graphene oxide (rGO)/ZnS heterostructures coupled with reliable carrier migration channels and visible-light response antennas by building rGO-integrated electrochemical nanoreactors and an ion-exchange process. In this ternary catalyst, the Cd clusters and rGO perform as charge relays to boost carrier transport via the Z-scheme route and accelerate photogenerated carriers to react with surface-adsorbed substances. Meanwhile, thanks to CdS, the heterostructures have photocatalytic properties under visible light illumination and can also inhibit self-corrosion by shielding Cd clusters to avoid disrupting charge transfer channels. Therefore, the special heterostructure demonstrates fascinating photocatalytic hydrogen production activity without the intervention of cocatalysts. This work provides a feasible protocol for improving the interfaces between metals and semiconductors to achieve efficient photocatalytic hydrogen generation.

Highly Crystalline Poly(heptazine imide)-Based Carbonaceous Anodes for Ultralong Lifespan and Low-Temperature Sodium-Ion Batteries.

Carbon nitrides with layered structures and scalable syntheses have emerged as potential anode choices for the commercialization of sodium-ion batteries. However, the low crystallinity of materials synthesized through traditional thermal condensation leads to insufficient conductivity and poor cycling stability, which significantly hamper their practical applications. Herein, a facile salt-covering method was proposed for the synthesis of highly ordered crystalline C3N4-based all-carbon nanocomposites. The sealing environment created by this strategy leads to the formation of poly(heptazine imide) (PHI), the crystalline phase of C3N4, with extended π-conjugation and a fully condensed nanosheet structure. Meanwhile, theoretical calculations reveal the high crystallinity of C3N4 significantly reduces the energy barrier for electron transition and enables the generation of efficient charge transfer channels at the heterogeneous interface between carbon and C3N4. Accordingly, such nanocomposites present ultrastable cycling performances over 5000 cycles, with a high reversible capacity of 245.1 mAh g-1 at 2 A g-1 delivered. More importantly, they also exhibit an outstanding low-temperature capacity of 196.6 mAh g-1 at -20 °C. This work offers opportunities for the energy storage use of C3N4 and provides some clues for developing long-life and high-capacity anodes operated under extreme conditions.

The role of machine learning in advancing diabetic foot: a review.

Background: Diabetic foot complications impose a significant strain on healthcare systems worldwide, acting as a principal cause of morbidity and mortality in individuals with diabetes mellitus. While traditional methods in diagnosing and treating these conditions have faced limitations, the emergence of Machine Learning (ML) technologies heralds a new era, offering the promise of revolutionizing diabetic foot care through enhanced precision and tailored treatment strategies. Objective: This review aims to explore the transformative impact of ML on managing diabetic foot complications, highlighting its potential to advance diagnostic accuracy and therapeutic approaches by leveraging developments in medical imaging, biomarker detection, and clinical biomechanics. Methods: A meticulous literature search was executed across PubMed, Scopus, and Google Scholar databases to identify pertinent articles published up to March 2024. The search strategy was carefully crafted, employing a combination of keywords such as "Machine Learning," "Diabetic Foot," "Diabetic Foot Ulcers," "Diabetic Foot Care," "Artificial Intelligence," and "Predictive Modeling." This review offers an in-depth analysis of the foundational principles and algorithms that constitute ML, placing a special emphasis on their relevance to the medical sciences, particularly within the specialized domain of diabetic foot pathology. Through the incorporation of illustrative case studies and schematic diagrams, the review endeavors to elucidate the intricate computational methodologies involved. Results: ML has proven to be invaluable in deriving critical insights from complex datasets, enhancing both the diagnostic precision and therapeutic planning for diabetic foot management. This review highlights the efficacy of ML in clinical decision-making, underscored by comparative analyses of ML algorithms in prognostic assessments and diagnostic applications within diabetic foot care. Conclusion: The review culminates in a prospective assessment of the trajectory of ML applications in the realm of diabetic foot care. We believe that despite challenges such as computational limitations and ethical considerations, ML remains at the forefront of revolutionizing treatment paradigms for the management of diabetic foot complications that are globally applicable and precision-oriented. This technological evolution heralds unprecedented possibilities for treatment and opportunities for enhancing patient care.

Exploring the design of clinical research studies on the efficacy mechanisms in type 2 diabetes mellitus.

This review examines the complexities of Type 2 Diabetes Mellitus (T2DM), focusing on the critical role of integrating omics technologies with traditional experimental methods. It underscores the advancements in understanding the genetic diversity of T2DM and emphasizes the evolution towards personalized treatment modalities. The paper analyzes a variety of omics approaches, including genomics, methylation, transcriptomics, proteomics, metabolomics, and intestinal microbiomics, delineating their substantial contributions to deciphering the multifaceted mechanisms underlying T2DM. Furthermore, the review highlights the indispensable role of non-omics experimental techniques in comprehending and managing T2DM, advocating for their integration in the development of tailored medicine and precision treatment strategies. By identifying existing research gaps and suggesting future research trajectories, the review underscores the necessity for a comprehensive, multidisciplinary approach. This approach synergistically combines clinical insights with cutting-edge biotechnologies, aiming to refine the management and therapeutic interventions of T2DM, and ultimately enhancing patient outcomes. This synthesis of knowledge and methodologies paves the way for innovative advancements in T2DM research, fostering a deeper understanding and more effective treatment of this complex condition.

A Comparative Study of Removal of Acid Red 27 by Adsorption on Four Different Chitosan Morphologies.

To investigate the relationship between structures and adsorption properties, four different morphologies of chitosan, with hydrogel (CSH), aerogel (CSA), powder (CSP), and electrospinning nanofiber (CSEN) characteristics, were employed as adsorbents for the removal of Acid Red 27. The structures and morphologies of the four chitosan adsorbents were characterized with SEM, XRD, ATR-FTIR, and BET methods. The adsorption behaviors and mechanisms of the four chitosan adsorbents were comparatively studied. All adsorption behaviors exhibited a good fit with the pseudo-second-order kinetic model (R2 > 0.99) and Langmuir isotherm model (R2 > 0.99). Comparing the adsorption rates and the maximum adsorption capacities, the order was CSH > CSA > CSP > CSEN. The maximum adsorption capacities of CSH, CSA, CSP, and CSEN were 2732.2 (4.523), 676.7 (1.119), 534.8 (0.885), and 215.5 (0.357) mg/g (mmol/g) at 20 °C, respectively. The crystallinities of CSH, CSA, CSP, and CSEN were calculated as 0.41%, 6.97%, 8.76%, and 39.77%, respectively. The crystallinity of the four chitosan adsorbents was the main factor impacting the adsorption rates and adsorption capacities, compared with the specific surface area. With the decrease in crystallinity, the adsorption rates and capacities of the four chitosan adsorbents increased gradually under the same experimental conditions. CSH with a low crystallinity and large specific surface area resulted in the highest adsorption rate and capacity.

Advances in secondary prevention mechanisms of macrovascular complications in type 2 diabetes mellitus patients: a comprehensive review.

Type 2 diabetes mellitus (T2DM) poses a significant global health burden. This is particularly due to its macrovascular complications, such as coronary artery disease, peripheral vascular disease, and cerebrovascular disease, which have emerged as leading contributors to morbidity and mortality. This review comprehensively explores the pathophysiological mechanisms underlying these complications, protective strategies, and both existing and emerging secondary preventive measures. Furthermore, we delve into the applications of experimental models and methodologies in foundational research while also highlighting current research limitations and future directions. Specifically, we focus on the literature published post-2020 concerning the secondary prevention of macrovascular complications in patients with T2DM by conducting a targeted review of studies supported by robust evidence to offer a holistic perspective.

Visible-light-active elemental photocatalysts.

Seeking visible-light-active photocatalysts for efficient solar-energy conversion has become an intensifying endeavor worldwide. In this concept paper, general requirements for finding new visible-light-active photocatalysts are briefly introduced, and recent progress in exploring elemental photocatalysts for clean-energy generation and environmental remediation are reviewed. Finally, opportunities and challenges facing elemental photocatalysts are discussed.

α-Sulfur crystals as a visible-light-active photocatalyst.

We show that in contrast to conventional compound photocatalysts, α-sulfur crystals of cyclooctasulfur (S(8)) are a visible-light-active elemental photocatalyst. The α-S crystals were found to have the ability not only to generate ·OH radicals but also to split water in a photoelectrochemical process under both UV-vis and visible-light irradiation. Although the absolute activity obtained was low because of the large particle size and poor hydrophilicity of the α-S crystals studied, there is great potential for increasing the activity with the assistance of known strategies such as surface modification, nanoscaling, doping, and coupling with other photocatalysts.

Constructing Anatase-Brookite TiO2 Phase Junction by Thermal Topotactic Transition to Promote Charge Separation for Superior Photocatalytic H2 Generation.

Phase junctions of photocatalysts can promote the separation of photogenerated charge carriers for efficient utilization of the carriers. Construction of phase junctions and establishing their structure-performance relationship are still required. Herein, polycrystalline TiO2 decahedral plates with different phases were synthesized by thermal treatment-induced topotactic transition of titanium oxalate crystals. The phase of TiO2 evolved from pure anatase to anatase-brookite, anatase-brookite-rutile, and then to anatase-rutile, while the morphology of the decahedral plates was well maintained. The biphase anatase-brookite was found to be most efficient in photocatalytic hydrogen generation. Specifically, the hydrogen generation rate of the biphase anatase-brookite TiO2 was nearly 2.4 times greater than that of the biphase anatase-rutile TiO2. The spatially resolved surface photovoltage measurements indicate the more efficient separation of photogenerated charge carriers and thus greater photocatalytic activity of the former. This work provides a strategy for developing efficient phase-junction photocatalysts.

Simultaneous detection of circulating tumor DNAs using a SERS-based lateral flow assay biosensor for point-of-care diagnostics of head and neck cancer.

Circulating tumor DNA (ctDNA) has recently emerged as an ideal target for biomarker analytes. Thus, the development of rapid and ultrasensitive ctDNA detection methods is essential. In this study, a high-throughput surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) strip is proposed. The aim of this method is to achieve accurate quantification of TP53 and PIK3CA E545K, two types of ctDNAs associated with head and neck squamous cell carcinoma (HNSCC), particularly for point-of-care testing (POCT). Raman reporters and hairpin DNAs are used to functionalize the Pd-Au core-shell nanorods (Pd-AuNRs), which serve as the SERS probes. During the detection process, the existence of targets could open the hairpins on the surface of Pd-AuNRs and trigger the first step of catalytic hairpin assembly (CHA) amplification. The next stage of CHA amplification is initiated by the hairpins prefixed on the test lines, generating numerous "hot spots" to enhance the SERS signal significantly. By the combination of high-performing SERS probes and a target-specific signal amplification strategy, TP53 and PIK3CA E545K are directly quantified in the range of 100 aM-1 nM, with the respective limits of detection (LOD) calculated as 33.1 aM and 20.0 aM in the PBS buffer and 37.8 aM and 23.1 aM in human serum, which are significantly lower than for traditional colorimetric LFA methods. The entire detection process is completed within 45 min, and the multichannel design realizes the parallel detection of multiple groups of samples. Moreover, the analytical performance is validated, including reproducibility, uniformity, and specificity. Finally, the SERS-LFA biosensor is employed to analyze the expression levels of TP53 and PIK3CA E545K in the serum of patients with HNSCC. The results are verified as consistent with those of qRT-PCR. Thus, the SERS-LFA biosensor can be considered as a noninvasive liquid biopsy assay for clinical cancer diagnosis.

Effective modification of photocatalytic and piezocatalytic performances for poly(heptazine imide) by carbon dots decoration.

As the high-crystalline phase of carbon nitride, poly(heptazine imide) (PHI) has attracted much attention in recent years, considering the more effective light absorption, better charge carrier behavior, and higher surface area of PHI compared with its counterpart with a melon structure that is commonly synthesized through thermal polymerization. Nevertheless, exploring effective strategies to further improve the performance of PHI is still highly desirable. In this work, it is revealed that the photocatalytic as well as piezocatalytic performances of PHI are greatly promoted by coupling with carbon dots (CDots) through a facile ultrasonication process. Detailed structure characterizations indicate that a very low content of CDots (0.05%) decoration can double the light absorbance and achieve the efficient separation and transfer of photogenerated charge carriers. The optimal photocatalytic hydrogen evolution rate of PHI/CDots is about 2.49 and 2.81 times that of PHI, under UV-Visible and visible light irradiation, respectively. Moreover, the piezocatalytic H2O2 generation and KMnO4 degradation activities of PHI/CDots are around 2 times that of PHI. The results obtained in this work provide references for the modification of PHI and may inspire new strategies for the design of highly efficient carbonaceous photocatalysts.