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This paper provides an overview of recent studies on energy storage in bifunctional TiO2 composite materials under UV and visible light. The working mechanism, property improvements and applications of these bifunctional TiO2 composite systems are introduced, respectively. The latest results obtained in our laboratory, especially a new process for photoelectric conversion and energy storage in TiO2/Cu2O bilayer films under visible light, are also presented. Hopefully this review will stimulate more fundamental and applied research on this subject in the future.

Four nanostructured Au electrodes were prepared by a simple and templateless electrochemical deposition technique. After complexing with a biotinylated polythiophene derivative (PTBL), photocurrent generation and performance of PTBL/Au-nanostructured electrodes as photoelectrochemical biosensors were investigated. Among these four nanostructured Au electrodes, vertically oriented nanobranches on the electrode significantly improved the photoelectric conversion, because the vertically oriented nanostructures not only benefit light harvesting but also the transfer of the photogenerated charge carriers. Owing to this advantaged nanostructure, the PTBL/Au-nanobranch electrode showed higher sensitivity and faster response times in the photoelectrochemical detection of a streptavidin-biotin affinity reaction compared to a PTBL/Au-nanoparticle electrode.

Langmuir-Blodgett (LB) technology has attracted increasing interest to generate intelligent biomaterials combined with novel peptide molecules. In this work, the composite films based on palmitoyl pentapeptide-4 (PP4) and phthalocyanine dye molecules were prepared by LB technique. The aggregation forms of phthalocyanine dye molecules and the structures/properties of composite films were studied. UV-Vis, FT-IR and SEM and other characterizations proved that the LB films are successfully composited, which may be due to the H-bonding, π-π stacking and electrostatic forces. Interestingly, the TPPS/PP4 LB films show excellent acid-alkali gas response. In addition, the surface-enhanced Raman scattering (SERS) demonstrate that the TsNiPc/PP4 LB film exhibits surface-enhancing properties for crystal violet (CV) molecules. Furthermore, the result demonstrate that the prepared LB films show good photocurrent generation efficiency. This work provides new clues for the preparation of self-assembled films and their applications as gas sensors, SERS and photoelectric device. [Display omitted] • Explore composite films based on palmitoyl pentapeptide-4 and phthalocyanine dye molecules by Langmuir-Blodgett technique. • Investigate the good acid-alkali gas response and surface-enhanced Raman scattering (SERS). • Provide new insight on chiral self-assembled LB films. [ABSTRACT FROM AUTHOR]

Light-responsive nanochannels have attracted extensive attention due to their noninvasive external field control and intelligent ion regulation. However, the limited photoresponsive current and the low photoelectric conversion efficiency still restrict their development. Here, a light-controlled nanochannel composed of 4-aminothiophenol and gold nanoparticles-modified mesoporous titania nanopillar arrays and alumina oxide (4-ATP-Au-MTI/AAO) is fabricated by the interfacial super-assembly strategy. Inspired by the process of electron transfer between photosystem I and photosystem II, the efficient electron transfer between TiO 2 , AuNPs, and 4-ATP under light is achieved by coupling the photoresponsive materials and functional molecules. Under illumination, 4-ATP is oxidized to p -nitrothiophenol (PNTP), which brings about changes in the wettability of the nanochannel, resulting in significant improvement (252.8%) of photoresponsive current. In addition, under the action of the reductant, the nanochannels can be restored to the initial dark state, enabling multiple reversible cycles. This work opens a new route for the fabrication of high-performance light-controlled nanochannels by coupling light-responsive materials and light-responsive molecules, which may guide the development of photoelectric conversion nanochannel systems.

Purpose: A PET/CT system's imaging capabilities are best described by its point spread function (PSF) in the spatial domain or equivalently by its modulation transfer function (MTF) in the spatial frequency domain. Knowing PSFs or MTFs is a prerequisite for many numerical methods attempting to improve resolution and to reduce the partial volume effect. In PET/CT, the observed PSF is a convolution of the system's intrinsic imaging capabilities including image reconstruction (PSF0) and the positron range function (PRF) of the imaged β+ emitting isotope. A PRF describes the non-Gaussian distribution of β+ annihilation events around a hypothetical point source. The main aim was to introduce a new method for determining a PET/CT system's intrinsic MTF (MTF0) from phantom measurements of hot spheres independently of the β+ emitting isotope used for image acquisition. Secondary aim was to examine non-Gaussian and nonlinear MTFs of a modern iterative reconstruction algorithm. Methods: PET/CT images of seven phantom spheres with volumes ranging from 0.25 to 16 ml and filled either with 18F or with 68Ga were acquired and reconstructed using filtered back projection (FBP). MTFs were modeled with linear splines. The spline fit iteratively minimized the mean squared error between the acquired PET/CT image and a convolution of the thereof derived PSF with a numerical representation of the imaged hot phantom sphere. For determining MTF0, the numerical sphere representations were convolved with a PRF, simulating a fill with either 18F or 68Ga. The MTFs determined by this so-called MTF fit method were compared with MTFs derived from point source measurements and also compared with MTFs derived with a previously published PSF fit method. The MTF fit method was additionally applied to images reconstructed by a vendor iterative algorithm with PSF recovery (Siemens TrueX). Results: The MTF fit method was able to determine 18F and 68Ga dependent MTFs and MTF0 from FBP reconstructed images. Root-mean-square deviation between fit determined MTFs and point source determined MTFs ranged from 0.023 to 0.039. MTFs from Siemens TrueX reconstructions varied with size of the imaged sphere. Conclusions: MTF0 can be determined regardless of the imaged isotope, when using existing PRF models for the MTF fit method presented. The method proves that modern iterative PET/CT reconstruction algorithms have nonlinear imaging properties. This behaviour is not accessible by point source measurements. MTFs resulting from these clinically applied algorithms need to be estimated from objects of similar geometry to those intended for clinical imaging. [ABSTRACT FROM AUTHOR]

As a solar cell a heterostructure has been proposed that consists of an anode copper oxide CuO and a transparent conductive layer Cd-Sn-O obtained via extraction-pyrolytic method. The heterostructure is formed on a copper substrate by means of anodic oxidation with further applying a transparent conductive oxide film. An increase in the efficiency of the CuO/Cd-Sn-O element compared with Cu-CuO structure has been shown to be possible. [ABSTRACT FROM AUTHOR]

Purpose: Small field output correction factors have been studied by several research groups for the PTW 60019 microDiamond (MD) dosimeter, by comparing the response of such a device with both reference dosimeters and Monte Carlo simulations. A general good agreement is observed for field sizes down to about 1 cm. However, evident inconsistencies can be noticed when comparing some experimental results and Monte Carlo simulations obtained for smaller irradiation fields. This issue was tentatively attributed by some authors to unintentional large variations of the MD active surface area. The aim of the present study is a nondestructive experimental determination of the MD active surface area and active volume. Methods: Ten MD dosimeters, one MD prototype, and three synthetic diamond samples were investigated in the present work. 2D maps of the MD response were recorded under scanned soft x-ray microbeam irradiation, leading to an experimental determination of the device active surface area. Profiles of the device responses were measured as well. In order to evaluate the MD active volume, the thickness of the diamond sensing layer was independently evaluated by capacitance measurements and alpha particle detection experiments. The MD sensitivity, measured at the PTW calibration laboratory, was also used to calculate the device active volume thickness. Results: An average active surface area diameter of (2.19±0.02) mm was evaluated by 2D maps and response profiles of all the MDs. Average active volume thicknesses of (1.01±0.13) µm and (0.97±0.14) µm were derived by capacitance and sensitivity measurements, respectively. The obtained results are well in agreement with the nominal values reported in the manufacturer dosimeter specifications. A homogeneous response was observed over the whole device active area. Besides the one from the device active volume, no contributions from other components of the housing nor from encapsulation materials were observed in the 2D response maps. Conclusions: The obtained results demonstrate the high reproducibility of the MD fabrication process. The observed discrepancies among the output correction factors reported by several authors for MD response in very small fields are very unlikely to be ascribed to unintentional variations of the device active surface area and volume. It is the opinion of the authors that the role of the volume averaging as well as of other perturbation effects should be separately investigated instead, both experimentally and by Monte Carlo simulations, in order to better clarify the behaviour of the MD response in very small fields. [ABSTRACT FROM AUTHOR]

Thin films consisting of zinc oxide or titanium dioxide particles dispersing an organic ligand, i.e., 1,2-dihydroxynaphthalene (DHN) or 8-hydroxyquinoline (HQ), on the surface were prepared by the sol–gel method with steam treatment. The crystalline phases were identified by XRD analysis. The UV–vis absorption and photocurrent spectra of the films were analyzed for their photoelectrochemical characterization. The complex formation of the ligands was confirmed by FTIR spectroscopy. The ligand molecules formed zinc complexes in the interlayer of the layered zinc hydroxide which was formed on the zinc oxide surface. The zinc complex did not efficiently generate electricity because the electron injection from the DHN moiety or the zinc complex of HQ into the zinc oxide was blocked by the layered zinc hydroxide. The ligand molecules formed titanium complexes on the titanium dioxide surface, and also zinc complexes in the presence of zinc ions on the titanium dioxide surface. The zinc complex formation increased the photocurrent. It is suggested that electrons were directly injected from the DHN moiety into the titanium dioxide conduction band and indirectly injected from the excited states of the metal complex of HQ into the titanium dioxide conduction band. [ABSTRACT FROM AUTHOR]

Eosin Y-adsorbing ZnO thin films were prepared on substrates by electroless deposition from aqueous solutions containing zinc nitrate, dimethylamine−borane, and eosin Y. The concentration of eosin Y in the solution changed the structure of the deposited ZnO particles on the substrate. In the absence of eosin Y in the solution, the ZnO crystals preferred to grow in the c-axis direction. In the presence of eosin Y in the solution, the orientation of the ZnO was in the a-axis direction. As the eosin Y concentration increased, the size of the ZnO crystallites decreased and they became aggregated due to a strong interaction between the eosin Y and the (0002) plane of the ZnO, and consequently, the film resistance increased due to their boundary. The electron injection efficiency increased due to the strong interaction although the electron transfer efficiency decreased. The ZnO crystallite size, eosin Y amount, and their interaction increased the energy conversion efficiency. [ABSTRACT FROM AUTHOR]

Purpose: Many centers aim to plan liver transarterial radioembolization (TARE) with dosimetry, even without CT-based attenuation correction (AC), or with unoptimized scatter correction (SC) methods. This work investigates the impact of presence vs absence of such corrections, and limited spatial resolution, on 3D dosimetry for TARE. Methods: Three voxelized phantoms were derived from CT images of real patients with different body sizes. Simulations of 99mTc-SPECT projections were performed with the SIMIND code, assuming three activity distributions in the liver: uniform, inside a "liver's segment," or distributing multiple uptaking nodules ("nonuniform liver"), with a tumoral liver/healthy parenchyma ratio of 5:1. Projection data were reconstructed by a commercial workstation, with OSEM protocol not specifically optimized for dosimetry (spatial resolution of 12.6 mm), with/without SC (optimized, or with parameters predefined by the manufacturer; dual energy window), and with/without AC. Activity in voxels was calculated by a relative calibration, assuming identical microspheres and 99mTc-SPECT counts spatial distribution. 3D dose distributions were calculated by convolution with 90Y voxel S-values, assuming permanent trapping of microspheres. Cumulative dose-volume histograms in lesions and healthy parenchyma from different reconstructions were compared with those obtained from the reference biodistribution (the "gold standard," GS), assessing differences for D95%, D70%, and D50% (i.e., minimum value of the absorbed dose to a percentage of the irradiated volume). tool analysis with tolerance of 3%/13 mm was used to evaluate the agreement between GS and simulated cases. The influence of deep-breathing was studied, blurring the reference biodistributions with a 3D anisotropic gaussian kernel, and performing the simulations once again. Results: Differences of the dosimetric indicators were noticeable in some cases, always negative for lesions and distributed around zero for parenchyma. Application of AC and SC reduced systematically the differences for lesions by 5%-14% for a liver segment, and by 7%-12% for a nonuniform liver. For parenchyma, the data trend was less clear, but the overall range of variability passed from -10%/40% for a liver segment, and -10%/20% for a nonuniform liver, to -13%/6% in both cases. Applying AC, SC with preset parameters gave similar results to optimized SC, as confirmed by tool analysis. Moreover, analysis confirmed that solely AC and SC are not sufficient to obtain accurate 3D dose distribution. With breathing, the accuracy worsened severely for all dosimetric indicators, above all for lesions: with AC and optimized SC, -38%/-13% in liver's segment, -61%/-40% in the nonuniform liver. For parenchyma, D50% resulted always less sensitive to breathing and sub-optimal correction methods (difference overall range: -7%/13%). Conclusions: Reconstruction protocol optimization, AC, SC, PVE and respiratory motion corrections should be implemented to obtain the best possible dosimetric accuracy. On the other side, thanks to the relative calibration, D50% inaccuracy for the healthy parenchyma from absence of AC was less than expected, while the optimization of SC was scarcely influent. The relative calibration therefore allows to perform TARE planning, basing on D50% for the healthy parenchyma, even without AC or with suboptimal corrections, rather than rely on nondosimetric methods. [ABSTRACT FROM AUTHOR]

The combination of solar cells and rechargeable batteries has been confirmed as a new strategy for the development of solar energy utilization. However, the high charging voltage of Li-ion battery (3.0–4.2 V) and incompatible electrolyte with solar cell is adverse to the combination of photo-assisted rechargeable battery (PRB). In this work, Li–S battery as an energy storage unit is combined with dye-sensitized solar cell to form an integrated three-electrode photo-assisted rechargeable Li–S battery (PRSB). The compatible C/S electrode provides a bridge for realizing the bi-function of photoelectric conversion and storage. In contrast to the dual electrolytes in the previously reported PRBs, lithium bis((trifluoromethyl)sulfonyl)azanide (LiTFSI), namely the highly compatible mono-electrolyte in our newly designed PRSB with three-electrode, facilitates the charge separation and enhances the capacity and stability of integrated photo-assisted rechargeable battery. With the compensation of photogenerated carrier, the charge voltage of PRSB drops 0.12 V and the discharge capacity increases to 885 mAh g−1 under solar charging, indicating that the integrated device is promising to save electric energy and improve the performance of PRBs. [Display omitted] • An integrated photo-assisted rechargeable Li–S battery (PRSB) was designed. • Bi-function of photoelectric conversion and storage is realized by novelty battery. • The bi-functional electrode in mono-electrolyte improve the compatibility of PRSB. • The PRSB can reduce the charging voltage and increase capacity under illumination. [ABSTRACT FROM AUTHOR]

The development of multifunctional film materials from novel organic small molecules has attracted the attention of researchers. In this study, novel carbazole organic molecules (CS-14, CS-38 and CS-39) were successfully composited with TsNiPc and TPPS subphases into multilayer films by LB technology. The nanostructure and morphology of the composite films were successfully assembled and analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the stability of the composite film was proved by UV–vis spectroscopy and Fourier transform infrared spectroscopy. The results demonstrate that Langmuir films are transferred to the surface of substrates in different aggregated morphologies. In addition, the self-assembled LB film electrodes exhibit excellent photoelectrochemical performance. The photoelectric conversion of the multilayer films transferred to ITO (indium tin oxide) was tested, and CS-38/TsNiPc Langmuir film exhibits a stronger photoelectric conversion effect. The electrolysis reaction of LB films to water was also tested. Further analysis shows that the composite films with TsNiPc as the subphase all showed better catalytic performance than the composite films with TPPS as the subphase. Therefore, the prepared LB film has the potential to become an optoelectronic functional ultrathin film device. [Display omitted] • Develop novel carbazole-based organic molecule composite Langmuir-Blodget films. • Demonstrate the photoelectric conversion and catalytic performance. • Self-assembled film showed high photoelectric conversion efficiency. • Potential applications in optoelectronic functional device. [ABSTRACT FROM AUTHOR]

Integrating a noble metal with a semiconductor is a feasible pathway to improve the photoelectric conversion behavior of materials. In this work, a novel composite made up of three dimensional (3D) Ag nanodendrites (AgNDs) and two dimensional (2D) MoS 2 nanosheets was integrated via a facile electrodeposition approach. The characterization results show that cubic phase AgNDs are enwrapped by MoS 2 nanosheets in MoS 2 /AgNDs composite. Interestingly, since the existence of MoS 2 provided trapping sites for the plasmon-excited thermal electrons of AgNDs and in turn the AgNDs acted as a “pool” to gather photoexcited electrons of the MoS 2 , the invalid recombination of the photoexcited electron–hole pairs was greatly suppressed. Therefore, the MoS 2 /AgNDs composite showed excellent photoelectric conversion property. [ABSTRACT FROM AUTHOR]

Recently bendable and flexible optoelectronics have attracted more attentions on display technology and concaved or curvy photovoltaic devices owing to the flexibility and softy in layered materials. The bending photoluminescence (BPL) and surface photovoltaic effect of a thin multilayer InSe 2D crystal are demonstrated here by using PL and surface photovoltage (SPV) experiments. The BPL result of InSe (t ≈ 30 nm) shows an enhancement in light intensity with respect to that of the other flat PL measurement owing to the spreading of emission solid angle for the irradiant Se‐In‐In‐Se basic units under concaved upward condition. The band edge structure of multilayer InSe is analyzed. The SPV measurement of an In mesh‐coated InSe microplate demonstrates that the Schottky‐type solar cell converts sunlight starting from ≈1 eV with the auxiliary of surface states on InSe. An initially formed In‐InSe Schottky solar cell (surface area of ≈2 mm2 and thickness of ≈85 μm) is also tested. The testing result shows a photovoltage of V ≈ 24 mV can be generated from the Schottky solar cell under the illumination of Hg lamp with power density of P ≈ 0.83 mW cm−2. All the experimental results demonstrate flexible light‐emission capability and “1 eV” photoelectric conversion capacity existed in the 2D multilayer ε‐InSe. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO)–ZnO nanocomposite films were synthesized on Fluorine doped Tin Oxide (FTO) coated glasses by electrochemical codeposition. The films have a laminated architecture with GO and ZnO alternate layers arranged basically parallel to the substrate. The structures of the composites were characterized using XRD, FE-SEM, FT-IR, XPS, Raman, UV–visible, and electrochemical cyclic voltammetry analyses. The results showed that by increasing Zn:C ratio of the suspensions, there is a series of structural evolutions of the composites, and the percentages of the C–O bonds of GO in the composites decreased. The decreased C–O bonds of GO indicate an increase in the reduction degree of GO, with which its energy gap varies from 1.99 eV to 0.89 eV. Moreover, the energy levels of GO and ZnO in the composites were determined. The results of photoelectrochemical measurements of the films indicated the feasibility of using GO in photoelectric conversion as photoabsorbers. A preliminary study on the relationship between the changes in the photocurrent and the structure of the films has provided clues for further studies on improving the photoelectric conversion properties. [ABSTRACT FROM AUTHOR]

Purpose: The radioligand 11C-KR31173 has been introduced for positron emission tomography (PET) imaging of the angiotensin II subtype 1 receptor in the kidney in vivo. To study the biokinetics of 11C-KR31173 with a compartmental model, the input function is needed. Collection and analysis of arterial blood samples are the established approach to obtain the input function but they are not feasible in patients with renal diseases. The goal of this study was to develop a quantitative technique that can provide an accurate image-derived input function (ID-IF) to replace the conventional invasive arterial sampling and test the method in pigs with the goal of translation into human studies. Methods: The experimental animals were injected with [11C]KR31173 and scanned up to 90 min with dynamic PET. Arterial blood samples were collected for the artery derived input function (AD-IF) and used as a gold standard for ID-IF. Before PET, magnetic resonance angiography of the kidneys was obtained to provide the anatomical information required for derivation of the recovery coefficients in the abdominal aorta, a requirement for partial volume correction of the ID-IF. Different image reconstruction methods, filtered back projection (FBP) and ordered subset expectation maximization (OS-EM), were investigated for the best trade-off between bias and variance of the ID-IF. The effects of kidney uptakes on the quantitative accuracy of ID-IF were also studied. Biological variables such as red blood cell binding and radioligand metabolism were also taken into consideration. A single blood sample was used for calibration in the later phase of the input function. Results: In the first 2 min after injection, the OS-EM based ID-IF was found to be biased, and the bias was found to be induced by the kidney uptake. No such bias was found with the FBP based image reconstruction method. However, the OS-EM based image reconstruction was found to reduce variance in the subsequent phase of the ID-IF. The combined use of FBP and OS-EM resulted in reduced bias and noise. After performing all the necessary corrections, the areas under the curves (AUCs) of the AD-IF were close to that of the AD-IF (average AUC ratio = 1±0.08) during the early phase. When applied in a two-tissue-compartmental kinetic model, the average difference between the estimated model parameters from ID-IF and AD-IF was 10% which was within the error of the estimation method. Conclusions: The bias of radioligand concentration in the aorta from the OS-EM image reconstruction is significantly affected by radioligand uptake in the adjacent kidney and cannot be neglected for quantitative evaluation. With careful calibrations and corrections, the ID-IF derived from quantitative dynamic PET images can be used as the input function of the compartmental model to quantify the renal kinetics of 11C-KR31173 in experimental animals and the authors intend to evaluate this method in future human studies. [ABSTRACT FROM AUTHOR]

Ionic liquid-modified metal sulfides/graphene oxide nanocomposites are prepared via a facile electrostatic adsorption. Ionic liquid (IL) is firstly used as surface modifier and structure-directing agent of metal sulfide (MS) crystallization process, obtaining ionic liquid modified-MS (IL-MS) nanoparticles with positive charges on surface. IL-MS/GO is obtained by electrostatic adherence between positively charged IL-MS and negatively charged graphene oxide (GO). The as-prepared sample shows enhanced photocurrent and highly efficient photocatalytic activity under visible light irradiation, indicating IL-MS/GO nanocomposites greatly promoted the separation of photogenerated electron–hole pairs. [ABSTRACT FROM AUTHOR]

Using graphene quantum dots (GQDs) and H 2 SeO 3 as precursors, the reduced graphene quantum dots/Se nanowires (rGQDs/SeNWs) composite was electro-synthesized in the presence of cetyltrimethylammonium bromide (CTAB). The morphology and crystallization of the products as-synthesized was studied by a series of characterization techniques. The conductivity and photoresponse of rGQDs, Se NWs and rGQDs/SeNWs composite were determined respectively. Benefiting from the synergistic action of electron-deficient rGQDs and electron-rich Se NWs, significantly, the rGQDs/SeNWs composite showed excellent photoelectric conversion. [ABSTRACT FROM AUTHOR]

As semiconductor nanocrystals, quantum dots (QDs) have attracted great interest in recent years in chemical and biological detection due to their attractive optoelectronic characteristics. Biosensing of QD-based photoelectric conversion mainly includes electrochemiluminescence (ECL) and photoelectrochemical (PEC) sensing. Different authors have published overviews of bioanalytical applications of QDs. However, there has been no specific review on the use of QD-based systems for ECL and PEC bioanalysis. In this overview, we review novel methods and sensing principles based on using QDs for ECL and PEC sensing. We then provide an outlook on the future of the QD-based ECL and PEC biosensors. [ABSTRACT FROM AUTHOR]

In the third generation photovoltaic device, the main physical mechanism that the photoelectric conversion efficiency is enhanced is the singlet fission (SF). In order to accurately describe the SF and reveal physical process in theoretically, we introduce the anomalous processes (APs) in SF dynamics based on previous model, including anomalous fission, anomalous fusion, anomalous dissociation and combination of triplet pair states, anomalous decay and diffusion of single triplet exciton. The effects of the APs on SF are investigated by the kinetic model with time-dependent coefficient. Further, according to the effects the optimal simulations for the experimental data [G. B. Piland et al., J. Phys. Chem. C, 2013, 117, 1224] are given by adjusting the rate coefficients and exponents in the mended kinetic equations. The results show that the model containing APs is more accurate than previous that to describe SF dynamics, demonstrating that the APs do exist in SF. The model also provides the theoretical foundation for how varies experimentally physical parameters to make SF occur in the required direction. • In this paper, the main highlight is that the anomalous processes were introduced in the dynamics describing singlet fission process. • Besides, It was demonstrated that the anomalous processes exist in real singlet fission process, and the mended dynamics equations are more precise to describe singlet fission than previous that. • In fact, it also suggests that the nonlinear relations among the population of the spin states in singlet fission exist. [ABSTRACT FROM AUTHOR]