A dense array of CdS–ZnS core–shell nanorods film (1D vertically aligned) was synthesized through a simple two-step aerosol assisted chemical vapor deposition (AACVD) method. In this configuration, a ZnS nanocrystal (protective shell) was grown in situ on a CdS core, forming nanorod heterostructures to restrain the photo-corrosion and enhance the charge separation and transportation efficiencies of CdS cores. The as-prepared CdS–ZnS films showed elevated photoelectrochemical (PEC) performance (over four times than that of uncoated CdS arrays) with a significant photocurrent density of 7.8 mA cm−2 (0 V, vs. SCE) and incident photon to electron conversion efficiency (IPCE) values above 35% under AM 1.5G irradiation. Moreover, the stability of the photoelectrode was tested for over 16 min. These results suggest that the dense array of CdS–ZnS core–shell heterostructures provides a unique spatial distribution of the photo-excited charge carriers, as well as stable anti-photo-corrosion ability, and therefore is promising to be a photoelectrode in PEC hydrogen generation from water.

Optoelectronic lanthanide coordination polymer is a formidable challenge, because of its labile structure during device fabrication and incident emission quenching. In this work, an efficient electroluminescent (EL) one-dimensional Eu3+ coordination polymer, named Eu-FDPO, is first achieved with structural feature of bidentate phosphine oxide ligand FDPO bridged Eu(DBM)3 complex units (DBM is dibenzoylmethane). X-ray diffraction analysis verified preserved one-dimensional-chain structure of spin-coated Eu-FDPO film on the basis of stable and flexible coordination between FDPO and Eu3+ ion, making its device fabrication feasible. Wolf-III type configuration endows Eu-FDPO with unique and preeminent physical properties, especially high photoluminescent quantum yield over 80% in film, suitable frontier molecular orbital energy levels for effective charge injection and peculiar intra-chain carrier transportation with high electron mobility close to 10−6 cm2 V−1 s−1, indicating the predominance of Wolf-III type lanthanide coordination polymers in optoelectronic applications to their Wolf-I and II type counterparts. It is shown that FDPO is crucial as an intermediate in optoelectronic processes to establish channels for efficient intra-chain energy and charge transfer. Consequently, double-layer spin-coated devices of Eu-FDPO realized the best EL performance among Eu3+ coordination polymers to date, including low driving voltage of 10.2 V at 100 cd m−2 and high luminance and efficiency with maxima of 215 cd m−2 and 0.71 cd A−1, respectively, as well as unique single-polymer white EL emission with favorable color coordinates of (0.38, 0.32).

Water-dispersed reduced graphene oxide/chitosan oligosaccharide (RGO-CTSO) was prepared by chemical reduction of graphene oxide and synchronous functionalization with biocompatible chitosan oligosaccharide (CTSO). ζ potential measurement indicated that RGO-CTSO was highly stable in the acidic aqueous solution. RGO-CTSO was used to modify glassy carbon electrode (GCE) as the growth template of Escherichia coli (E. coli). The enhanced direct electron transfer of E. coli on the RGO-CTSO-modified GCE was studied by cyclic voltammetry. Compared with GCE or RGO-modified GCE, RGO-CTSO-modified GCE was more suitable for the adhesion growth of E. coli to improve direct electron transfer. The biocompatibility and versatility of RGO-CTSO made it promising for use as an anode material in microbial fuel cells.Keywords: chitosan oligosaccharide; direct electron transfer; Escherichia coli; reduced graphene oxide;

The concentration effect on the photoluminescence (PL) of the praseodymium Pr3+ ion is studied at 298–12 K for barium gadolinium molybdate (BaGd2(MoO4)4, called BGM) crystals with a wide Pr3+ concentration range of 0.05–25.0 mol%. Three types of concentration dependences are observed for the emissions although all types show PL quenching at high concentrations. The first type (Type A) has the maximum PL intensity at about 10 mol% with a non-zero intensity at high concentrations, which is observed for the 3P0 emissions except for emission at 621 nm. The second and third types (Type B-1 and B-2) have the maximum at about 1 mol% with a finite residual intensity and nearly zero intensity at high concentrations, respectively, which are observed for the 621 nm emission and all the 1D2 emissions. It is suggested that the energy migration mechanism is responsible for Type A, while the non-resonant cross-relaxation is responsible for Type B-1 and the resonant cross-relaxation for Type B-2.

In this work, CuTPyP (TPyP = 5,10,15,20-tetrapyridylporphine) single crystalline 2D nanoplates and 3D polyhedra of nano-octahedrons and microspindles can be selectively obtained by changing the type as well as the concentration of the surfactant via a simple surfactant-assisted chemical solution method at room temperature. Under anionic surfactant of sodium dodecyl sulfate (SDS), high purity uniform nanoplates were obtained, while under cationic surfactant of cetyltrimethylammonium bromide or tetrabutylammonium bromide, monodispersed microspindles and nano-octahedrons were obtained. The as synthesized products are characterized by UV–vis spectroscopy, fluorescence emission spectroscopy, X-ray diffraction pattern, scanning electron microscopy, and transmission electron microscopy. The crystal growth mechanism in the presence of either positively charged or negatively charged surfactant was studied by changing the preparation parameters. The rational shaping mechanism for different surfactants was thus promoted. This work provides a simple and mild approach to obtain high-quality 2D MTPyP nanocrystals through an anionic surfactant controlled synthesis process. It should be transferable to the shape control of nano- or microscaled metal–organic materials with related growth mechanisms.

•BaGd2(MoO4)4:Yb3+ was first developed to be a near-infrared converter.•The polycrystal presents enhanced photosensitivity in the range of 260–375 nm.•BaGd2(MoO4)4:Yb3+ has an intense NIR emission around 1000 nm, which perfectly matches the maximum spectral response of Si-based solar cells.•BaGd2(MoO4)4:Yb3+ shows high quantum efficiency of 37%.Efficient conversion from ultraviolet (UV) light to near infrared (NIR) emission has been demonstrated in a series of BaGd2−xYbx(MoO4)4 (x=0.001−2.0, i.e., Yb3+ concentration=0.05–100 mol%) polycrystals. The samples presented enhanced photosensitivity below 375 nm. Under UV light, an intense NIR emission around 1000 nm from 2F5/2→2F7/2 transitions of Yb3+ was observed, which just corresponds to spectral response of Si solar cells. The emission intensity in NIR region showed a dependence on Yb3+ contents. Taking into account the photoluminescence quantum efficiency, the optimal doping to increase the conversion efficiency of Si-solar cells was suggested to be 20 mol%. Diffuse reflectance and luminescence spectra were also systematically investigated to propose a reasonable mechanism for energy conversion process from the photo-excited charge transfer states.

A micro-spectrometer with phase modulation array is investigated in this paper. The vital component of this micro-spectrometer is a micro-interferometer array, which is built on a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). Each element of micro-interferometer array is formed by polymethyl methacrylate (PMMA) grooves with different depth. When we illuminate the surface of the interferometer array, different interference intensity distribution would be formed at the bottom of each micro-interferometer. Optical power of this interferometer can be measured by the pixels of CCD or CMOS. The data can be substituted into a linear system. By solving the linear system with Tikhonov regularization method, spectrum of the incident beam can be reconstructed. Simulation results prove that the detection range of the spectrometer is a wide wavelength range covering from 300 to 1100 nm. Furthermore, the wavelength resolution of the device reaches picometer level. In comparison with conventional spectrometers, the novel spectrometer has distinct advantages of small size, low cost, high resolution, wide spectral measurement range, real-time measurement, and so on.

Hydrocarbon oligomers X9F, including S9F, D9F, and T9F as monomer, dimer, and trimer, respectively, were designed and prepared on the basis of indirect linkage and 9,9-diphenylfluorene (S9F) as repeat unit to form planar, linear, and V-shaped configurations without polarity variation and function amplification. The identical optical and electrochemical properties of X9F were achieved because of the effectively blocked intramolecualr electronic interactions by indirect linkage, including the same T1 value of 2.98 eV, high enough for hosts in blue phosphorescent organic light-emitting diodes (PHOLEDs), and the approximate FMO energy levels, which established the basis for selective investigation of independent configuration effect on the optoelectronic performance of host materials. Density function theory simulation manifested the frontier molecular orbital (FMO) location extension after oligomerization and the specific T1 locations on peripheral fluorenyls in X9F, giving rise to their different carrier-transporting abilities and host-localized triplet–triplet annihilation (TTA) and triplet–polaron quenching (TPQ) effects. As a result, D9F with the linear and locally unsymmetrical configuration revealed electron-predominant characteristics for charge balance, restrained triplet interaction for TTA suppression, and partially separated FMO and T1 locations for TPQ suppression. Consequently, the low driving voltages and the favorable maximum efficiencies, such as ∼11% for external quantum efficiency (EQE), as well as reduced roll-offs less than 8% for EQE at 1000 cd m–2, were achieved by D9F-based blue PHOLEDs as the highest performance among X9F, in which device efficiencies were improved by 50% compared to that of conventional polarized host mCP. It is conceivable that molecular configuration has significant effects on electrical properties and quenching effects of organic semiconductors with remarkable influence on intermolecular interplay and excited-state locations.

The concentration effect on the photoluminescence (PL) of the praseodymium Pr3+ ion is studied at 298–12 K for barium gadolinium molybdate (BaGd2(MoO4)4, called BGM) crystals with a wide Pr3+ concentration range of 0.05–25.0 mol%. Three types of concentration dependences are observed for the emissions although all types show PL quenching at high concentrations. The first type (Type A) has the maximum PL intensity at about 10 mol% with a non-zero intensity at high concentrations, which is observed for the 3P0 emissions except for emission at 621 nm. The second and third types (Type B-1 and B-2) have the maximum at about 1 mol% with a finite residual intensity and nearly zero intensity at high concentrations, respectively, which are observed for the 621 nm emission and all the 1D2 emissions. It is suggested that the energy migration mechanism is responsible for Type A, while the non-resonant cross-relaxation is responsible for Type B-1 and the resonant cross-relaxation for Type B-2.

A dense array of CdS–ZnS core–shell nanorods film (1D vertically aligned) was synthesized through a simple two-step aerosol assisted chemical vapor deposition (AACVD) method. In this configuration, a ZnS nanocrystal (protective shell) was grown in situ on a CdS core, forming nanorod heterostructures to restrain the photo-corrosion and enhance the charge separation and transportation efficiencies of CdS cores. The as-prepared CdS–ZnS films showed elevated photoelectrochemical (PEC) performance (over four times than that of uncoated CdS arrays) with a significant photocurrent density of 7.8 mA cm−2 (0 V, vs. SCE) and incident photon to electron conversion efficiency (IPCE) values above 35% under AM 1.5G irradiation. Moreover, the stability of the photoelectrode was tested for over 16 min. These results suggest that the dense array of CdS–ZnS core–shell heterostructures provides a unique spatial distribution of the photo-excited charge carriers, as well as stable anti-photo-corrosion ability, and therefore is promising to be a photoelectrode in PEC hydrogen generation from water.

Optoelectronic lanthanide coordination polymer is a formidable challenge, because of its labile structure during device fabrication and incident emission quenching. In this work, an efficient electroluminescent (EL) one-dimensional Eu3+ coordination polymer, named Eu-FDPO, is first achieved with structural feature of bidentate phosphine oxide ligand FDPO bridged Eu(DBM)3 complex units (DBM is dibenzoylmethane). X-ray diffraction analysis verified preserved one-dimensional-chain structure of spin-coated Eu-FDPO film on the basis of stable and flexible coordination between FDPO and Eu3+ ion, making its device fabrication feasible. Wolf-III type configuration endows Eu-FDPO with unique and preeminent physical properties, especially high photoluminescent quantum yield over 80% in film, suitable frontier molecular orbital energy levels for effective charge injection and peculiar intra-chain carrier transportation with high electron mobility close to 10−6 cm2 V−1 s−1, indicating the predominance of Wolf-III type lanthanide coordination polymers in optoelectronic applications to their Wolf-I and II type counterparts. It is shown that FDPO is crucial as an intermediate in optoelectronic processes to establish channels for efficient intra-chain energy and charge transfer. Consequently, double-layer spin-coated devices of Eu-FDPO realized the best EL performance among Eu3+ coordination polymers to date, including low driving voltage of 10.2 V at 100 cd m−2 and high luminance and efficiency with maxima of 215 cd m−2 and 0.71 cd A−1, respectively, as well as unique single-polymer white EL emission with favorable color coordinates of (0.38, 0.32).