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Few-Layered 1T-MoS2-Modified ZnCoS Solid-Solution Hollow Dodecahedra for Enhanced Photocatalytic Hydrogen Evolution
摘要： Enhancing solar hydrogen production efficiency essentially relies on the modification of low-cost and highly stable photocatalysts with enhanced light-harvesting ability and promoted charge transfer kinetics. Herein, we report a facile synthetic route to modify the performance of a low-cost metal sulfide semiconductor, consisting of the bimetallic metal-organic frameworks (MOFs)-templating and the simultaneous sulfidation of the photocatalyst and loading of MoS2 co-catalyst. The mutual sulfur atom shared by all the transition metal sulfides allowed the formation of ZnCoS solid-solution structure and the stabilization of the metallic 1T-MoS2 phase, contributing to the photocatalytic activity enhancement from several aspects: i) extending the light absorption region from UV to visible and near-infrared light by the incorporation of another transition metal sulfide species, i.e., CoS; ii) achieving abundant catalytically active sites, and high electronic conductivity between the intimately contacted ZnCoS and MoS2 by loading few-layered 1T-MoS2; and iii) further increasing its capability of utilizing the single-photon with relatively higher energy in the UV-visible region by the involvement of a metal-free photosensitizer–Eosin Y (EY). As a consequence, the novel few-layered 1T MoS2-modified hollow Zn0.5Co0.5S rhombic dodecahedra exhibited a high photocatalytic H2 production activity of 15.47 mmol h-1 g-1 with an apparent quantum efficiency of 30.3% at 420 nm and stability with 90% H2 evolution retention even after seven consecutive runs for total 35 h irradiation. This novel approach to prepare advanced materials could be further extended to the phase-controllable preparation of MoS2 and the discovery of other transition metal chalcogenides with high activity and stability in various applications.
关键词： ZnCoS solid-solution,hollow dodecahedra,dye-sensitization,1T-MoS2,photocatalytic hydrogen evolution,MOF-templating
更新于2025-11-21 10:59:37
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CuInS2 sensitized TiO2 for enhanced photodegradation and hydrogen production
摘要： A novel CuInS2/TiO2 (CIS-TO) heterojunction which displayed two different transfer pathways of photo-generated carries under UV–vis and Vis light irradiation was fabricated through a facile in-situ growth method. Under vis-light (λ ≥ 420 nm) excitation, 97.37% RhB (10 mg/L) was photodegraded with 20 mg of 1% CIS-TO photocatalyst within 90 min, and the degradation constant could up to 0.0415 min?1, which was about 8.28 times to pure TiO2 (0.00501 min?1) and the typical heterojunction was formed between CuInS2 and TiO2 to provide the photo-electrons transfer channel. Under UV–vis light irradiation, a Z-scheme heterojunction was formed to provide another highly effective electron transfer channel for hydrogen production and the hydrogen production rate could reach 785.4 μmol g?1 h?1 with 1% CIS-TO photocatalyst, which showed nearly 1.68 times than that of pure TiO2. The enhanced photocatalytic activity could be attributed to the synergistic effect of the sensitization and narrow band gap of CuInS2 which could effectively broaden the spectral response range, enhance the photon utilization and inhibit the recombination of photogenerated electrons and holes. Additionally, the high stability of the material was illustrated by the cycle experiments of photodegradation and hydrogen production.
关键词： Typical heterojunction,Sensitization,Z-scheme heterojunction,Photodegradation,CuInS2/TiO2
更新于2025-09-23 15:23:52
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Challenges in semiconductor single entity photoelectrochemistry
摘要： It is challenging to study the single semiconductor (SC) nanocrystal electrochemistry and photoelectrochemistry. The photocatalytic process that results from the electron-hole pair formed within a nanoparticle (NP) like the oxidation of methanol and iodide allow the detection of discrete current transient events assigned to single entities. Photocatalytic current amplification allows detection of collisions between the semiconductor NPs and the ultramicroelectrode (UME) that produce current transient. Staircase responses and blips in the i vs. t response indicate that irreversible and reversible NP/electrode interactions result depending on the experimental conditions. Dye sensitization increases the photocurrent magnitude of ZnO and TiO2 with respect to bare TiO2 NPs. The microelectrodes used are Pt, TiO2/Pt, TiO2/Au and F-doped SnO2 (FTO).
关键词： semiconductor,photoelectrochemistry,ultramicroelectrode,nanoparticle,dye sensitization,single entity
更新于2025-09-23 15:23:52
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Carbon Nanotube-Supported Cu <sub/>3</sub> P as High-Efficiency and Low-Cost Cocatalysts for Exceptional Semiconductor-Free Photocatalytic H <sub/>2</sub> Evolution
摘要： Developing an inexpensive and high-efficiency hydrogen-production cocatalyst to replace the noble metal Pt remains a big challenge in the fields of sustainable photocatalytic hydrogen evolution. Herein, we report the exploration of a high-efficient binary noble metal free Cu3P-CNT H2-evolution cocatalyst by direct high-temperature phosphatizing of Cu(OH)2-CNT. Impressively, combining the advantages of noble metal free Cu3P and carbon nanotube (CNT), the binary Cu3P-CNT cocatalysts show high-efficient photocatalytic H2 evolution in Eosin Y(EY)-contained semiconductor-free photocatalytic systems. The maximum visible-light H2-generation rate for promising EY-Cu3P-CNT systems was 17.22 mmolg-1h-1. The highest apparent quantum efficiency (AQE) could reach 10.23% at 500 nm. More importantly, we found that the separation of photogenerated electrons and holes in the Eosin Y, the efficiency of electron transfer from EY to the active edge sites of Cu3P, and the electrocatalytic H2-evolution activity of Cu3P, could be simultaneously boosted via readily adding the conductive CNT, thus achieving the significantly improved photocatalytic H2 evolution. This work provides a simple and facile strategy to design highly efficient semiconductor-free photocatalytic proton-reduction systems using high-activity transition metal phosphides (TMPs) and inexpensive carbon nanomaterials.
关键词： Photocatalytic Hydrogen Evolution,noble metal-free Cu3P Co-catalysts,Solar Fuel,Carbon nanotube (CNT),Dye sensitization
更新于2025-09-23 15:23:52
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Host Sensitized Lanthanide Photoluminescence from Post-synthetically Modified Semiconductor Nanoparticles Depends on Reactant Identity
摘要： This work investigates the photoluminescence characteristics where cadmium selenide (CdSe) and zinc sulfide (ZnS) nanoparticles are treated post-synthetically by the trivalent lanthanide cations (Ln3+) [Ln = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb] separately to form either CdSe/Ln or ZnS/Ln nanoparticles. Host sensitized Ln3+ emission was found to be present only in CdSe/Eu, CdSe/Tb, ZnS/Eu, ZnS/Tb and ZnS/Yb nanoparticles. In all the cases tuning of emission of the nanoparticles has been observed, irrespective of the presence or absence of host sensitization. The elemental compositions of CdSe and ZnS nanoparticles upon post-synthetic treatment show a remarkable difference. Incorporation of lanthanides in the nanoparticles is evident with significant alteration in the anionic content, and complete cation exchange of either Cd2+ or Zn2+ by Ln3+ has not been detected; as evaluated from energy dispersive X-ray spectroscopy. Further evaluation on this comes from considering thermodynamic parameters of inter cation interaction. In cases where the host sensitized Ln3+ emission have been observed, luminescence lifetime measurements reveal significant protection of Ln3+ in the nanoparticles. Noticeable difference in photophysical properties for a given Ln3+ has been realized in the two hosts. The photophysical observations have been rationalized using (i) charge trapping mediated host sensitized dopant emission, (ii) autoionization of excited electrons, and (iii) environment induced photoluminescence quenching. The post-synthetic modification discussed in the present work provides an easy and less synthetically demanding room temperature based protocol to avail lanthanide incorporated (doped) semiconductor nanoparticles that can potentially use the unique emission properties of the lanthanide cations.
关键词： Semiconductor Nanoparticles,Host Sensitization,Trivalent Lanthanides,Photoluminescence,Post-synthetic Modification
更新于2025-09-23 15:23:52
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A highly sensitive photocatalytic plastic optic-fiber sensor for selective detection of phenol in aqueous solutions
摘要： We present a highly sensitive photocatalytic plastic optic-fiber (POF) sensor for the selective detection of phenol in aqueous solutions. To obtain high sensitivity and low limit of detection (LOD) of the sensor, part of the POF cladding was removed and replaced by a Canada balsam doped with GeO2 (CBG); a UV-visible-light-driven photocatalytic material, that is a CdS-sensitized Er3+YAlO3/SiO2/TiO2 (EYST) composite, was coated on the CBG film. To realize highly selective detection of phenol in water, a high phenol permselectivity and pH independence polymer membrane was fixed on the CdS-sensitized EYST-CBG-coated POF. Furthermore, a model was developed to show that the phenol concentration can be determined by measuring the change in transmitted light intensity of the POF sensor and the sensitivity of the sensors can be improved by employing the CdS-sensitized EYST film. The results showed that the proposed photocatalytic POF sensor has a high sensitivity of -0.39 (mg·mL-1)-1 and low LOD of 15 μg·L-1 for the selective detection of phenol in aqueous solutions with pH ranging from 2.0 to 14.0.
关键词： Cds sensitization,Phenol concentration,High sensitivity and selectivity,Upconversion luminescence agent,Plastic optical fiber,TiO2 composite film
更新于2025-09-23 15:23:52
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Selective Functionalization of High-Resolution Cu2O Nanopatterns via Galvanic Replacement for Highly Enhanced Gas Sensing Performance
摘要： Recently, high-resolution patterned metal oxide semiconductors (MOS) have gained considerable attention for enhanced gas sensing performance due to their polycrystalline nature, ultrasmall grain size (~5 nm), patternable properties, and high surface-to-volume ratio. Herein, we significantly enhanced the sensing performance of that patterned MOS by galvanic replacement, which allows for selective functionalization on ultrathin Cu2O nanopatterns. Based on the reduction potential energy difference between the base channel material (Cu2O) and the decorated metal ion (Pt2+), Pt could be selectively and precisely decorated onto the desired area of the Cu2O nanochannel array. Overall, the Pt-decorated Cu2O exhibited 11-fold higher NO2 (100 ppm) sensing sensitivity as compared to the non-decorated sensing channel, the while the channel device with excessive Pt doping showed complete loss of sensing properties.
关键词： galvanic replacement,chemical sensitization,p-type metal oxide,gas sensor,high-resolution,nanopattern
更新于2025-09-23 15:23:52
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[IEEE 2017 International Conference on Electron Devices and Solid-State Circuits (EDSSC) - Hsinchu (2017.10.18-2017.10.20)] 2017 International Conference on Electron Devices and Solid-State Circuits (EDSSC) - Influence of sensitization on the surface properties of PbSe thin films
摘要： This report focuses on the surface properties of sensitized polycrystalline lead selenide (PbSe) thin films that could significantly affect the final performance of photoconductive devices. By characterization the element chemical state and the current distribution along with the relevant morphologies at surface of sensitized and original PbSe films, it is confirmed that after sensitization surface properties, as well as the performance of photoconductive devices have been significantly modified. The mechanism was also discussed.
关键词： surface properties,lead selenide,photoconductive,sensitization
更新于2025-09-23 15:23:52
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Optimization of formaldehyde detection performance based on Ni2+ sensitized monodisperse amorphous zinc tin oxide microcubes
摘要： The pure and Ni2+ sensitized monodisperse amorphous zinc tin oxide (a-ZTO) microcubes were synthesized via an in-situ precipitation method and subsequent wet impregnation. XPS results revealed that Ni2+ sensitization increased the relative content of chemisorbed oxygen and oxygen vacancies on the surface of a-ZTO microcubes. Compared to pure a-ZTO microcubes, 0.75 at% Ni2+ sensitized a-ZTO microcubes can significantly improve the gas sensing performance to formaldehyde at 200 °C, which may be attributed to its uniform morphology and modification of Ni2+ on the surface of a-ZTO microcubes. Further, the gas sensing mechanism is briefly discussed.
关键词： Surface sensitization,Zinc tin oxide,Monodisperse,Amorphous material,Sensors
更新于2025-09-23 15:22:29
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Diphenylisobenzofuran Bound to Nanocrystalline Metal Oxides: Excimer Formation, Singlet Fission, Electron Injection, and Low Energy Sensitization
摘要： We report the photophysical properties of the dicarboxylated diphenylisobenzofuran dye (1) bound to nanocrystalline metal oxide surfaces. With increased surface loading of 1, emission from the films is significantly quenched but with a small amount of excimer emission at maximum surface loadings. Long-lived triplets were observed by ns TA spectroscopy that is consistent with singlet fission occurring on mesoporous ZrO2. The evolution of these triplets however could not be convincingly resolved by our sub-nanosecond TA spectroscopy. Dye-sensitized devices composed of 1 on a TiO2|Al2O3 core-shell structure exhibited an unusual decrease, increase, and then decrease in Jsc with respect to the thickness of Al2O3. In these films the Al2O3 acts as a tunneling barrier to slow electron injection from the singlet excited state such that singlet fission, and electron injection from the triplet state become competitive. Proof-of-principle self-assembled bilayer films that exhibit efficient triplet energy transfer from a low energy absorbing dye to 1 is demonstrated as another step towards a SF-based DSSC that can circumvent the Shockley-Queisser limit.
关键词： low energy sensitization,excimer formation,singlet fission,electron injection,diphenylisobenzofuran,nanocrystalline metal oxides
更新于2025-09-23 15:21:21