Palm-shaped optical spectrum generation for fiber-wireless integrated communication with dual-band millimeter wave capability

We proposed and demonstrated a simple cost-effective palm shaped spectrum generation based on DPMZM in order to simultaneously generating dual-band MMWs and optical carrier, offering an alternative in integration of fiber and wireless communication in indoor and inter-building environments.Published versio

Programmable Fiber-based in-band OSNR Monitoring for Flexgrid Coherent Optical Communication System

With the rapid development of ultra-dense large capacity coherent WDM optical communication networks, the monitoring of in-band optical signal-to-noise ratio (OSNR) plays an essential role to ensure signal qualities. Different from the classic polarization-nulling method, we proposed and experimentally demonstrated a novel fiber-based programmable in-band OSNR monitoring method for flexgrid coherent transmission system, the OSNR monitor is based on linearly chirped fiber Bragg grating (LCFBG) and commercial thermal print head (TPH). For the coherent communication system, when the output power of the pre-amplifier at the receiving terminal is constant, degraded OSNR leads to decreased signal power and elevated ASE noise. Therefore, if the central spectrum (signal and in-band noise) is filtered by an ultra-narrow bandwidth optical filter, the output optical power is in proportional to the OSNR value, the influence of the filtered in-band ASE noise will be negligible with relatively high OSNR and the ultranarrow bandpass filter is the key element for this technique. Based on the thermo-optic effect of the LCFBG, we used the in-house developed driver circuits and a LabVIEW based software to implement a programmable ultra-narrow passband optical filter for OSNR monitoring. Linear monitoring range of 9–27 dB OSNR values with wavelength ranging from 1530.6 to 1538 nm is achieved. The OSNR monitor has advantages of low cost, low insertion loss, large wavelength tunability and compatible with current optical fiber communication system.Published versio

Photonic generation of microwave signal with capability of arbitrary phase shifting using XPM in HNLF

Photonic generation of microwave signal with capability of full range phase tuning is proposed using XPM in the HNLF. Continuous phase shift with range of 360°is achieved together with compatible WDM operation.Published versio

Programmable bandwidth-variable optical temporal differentiator based on linearly chirped fiber bragg grating and digital thermal controller

We experimentally demonstrate an all-fiber structured bandwidth variable second-order optical temporal differentiator based on linearly chirped fiber Bragg grating and digital thermal controller. The bandwidth can be reconfigured from 0.55 nm to 0.8 nm.Published versio

Reactive template-derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

The development of economical, efficient, and robust electrocatalysts toward the hydrogen evolution reaction (HER) is highly imperative for the rapid advancement of renewable H-2 energy-associated technologies. Extensive utilization of the heterointerface effect can endow the catalysts with remarkably boosted electrocatalytic performance due to the modified electronic state of active sites. Herein, we demonstrate deliberate crafting of CoP/CoO heterojunction porous nanotubes (abbreviated as CoP/CoO PNTs hereafter) using a self-sacrificial template-engaged strategy. Precise control over the Kirkendall diffusion process of the presynthesized cobalt-aspartic acid complex nanowires is indispensable for the formation of CoP/CoO heterostructures. The topochemical transformation strategy of the reactive templates enables uniform and maximized construction of CoP/CoO heterojunctions throughout all the porous nanotubes. The establishment of CoP/CoO heterojunctions could considerably modify the electronic configuration of the active sites and also improve the electric conductivity, which endows the resultant CoP/CoO PNTs with enhanced intrinsic activity. Simultaneously, the hollow and porous nanotube architectures allow sufficient accessibility of exterior/interior surfaces and molecular permeability, drastically promoting the reaction kinetics. Consequently, when used as HER electrocatalysts, the well-designed CoP/CoO PNTs show Pt-like activity, with an overpotential of only 61 mV at 10 mA cm(-2) and excellent stability in 1.0 M KOH medium, exceeding those of the vast majority of the previously reported nonprecious candidates. Density functional theory calculations further substantiate that the construction of CoP/CoO heterojunctions enables optimization of the Gibbs free energies for water adsorption and H adsorption, resulting in boosted HER intrinsic activity. The present study may provide in-depth insights into the fundamental mechanisms of heterojunction-induced electronic regulation, which may pave the way for the rational design of advanced Earth-abundant electrocatalysts in the future

Reactive template-derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

The development of economical, efficient, and robust electrocatalysts toward the hydrogen evolution reaction (HER) is highly imperative for the rapid advancement of renewable H-2 energy-associated technologies. Extensive utilization of the heterointerface effect can endow the catalysts with remarkably boosted electrocatalytic performance due to the modified electronic state of active sites. Herein, we demonstrate deliberate crafting of CoP/CoO heterojunction porous nanotubes (abbreviated as CoP/CoO PNTs hereafter) using a self-sacrificial template-engaged strategy. Precise control over the Kirkendall diffusion process of the presynthesized cobalt-aspartic acid complex nanowires is indispensable for the formation of CoP/CoO heterostructures. The topochemical transformation strategy of the reactive templates enables uniform and maximized construction of CoP/CoO heterojunctions throughout all the porous nanotubes. The establishment of CoP/CoO heterojunctions could considerably modify the electronic configuration of the active sites and also improve the electric conductivity, which endows the resultant CoP/CoO PNTs with enhanced intrinsic activity. Simultaneously, the hollow and porous nanotube architectures allow sufficient accessibility of exterior/interior surfaces and molecular permeability, drastically promoting the reaction kinetics. Consequently, when used as HER electrocatalysts, the well-designed CoP/CoO PNTs show Pt-like activity, with an overpotential of only 61 mV at 10 mA cm(-2) and excellent stability in 1.0 M KOH medium, exceeding those of the vast majority of the previously reported nonprecious candidates. Density functional theory calculations further substantiate that the construction of CoP/CoO heterojunctions enables optimization of the Gibbs free energies for water adsorption and H adsorption, resulting in boosted HER intrinsic activity. The present study may provide in-depth insights into the fundamental mechanisms of heterojunction-induced electronic regulation, which may pave the way for the rational design of advanced Earth-abundant electrocatalysts in the future

Reactive template‐derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

Abstract The development of economical, efficient, and robust electrocatalysts toward the hydrogen evolution reaction (HER) is highly imperative for the rapid advancement of renewable H2 energy‐associated technologies. Extensive utilization of the heterointerface effect can endow the catalysts with remarkably boosted electrocatalytic performance due to the modified electronic state of active sites. Herein, we demonstrate deliberate crafting of CoP/CoO heterojunction porous nanotubes (abbreviated as CoP/CoO PNTs hereafter) using a self‐sacrificial template‐engaged strategy. Precise control over the Kirkendall diffusion process of the presynthesized cobalt–aspartic acid complex nanowires is indispensable for the formation of CoP/CoO heterostructures. The topochemical transformation strategy of the reactive templates enables uniform and maximized construction of CoP/CoO heterojunctions throughout all the porous nanotubes. The establishment of CoP/CoO heterojunctions could considerably modify the electronic configuration of the active sites and also improve the electric conductivity, which endows the resultant CoP/CoO PNTs with enhanced intrinsic activity. Simultaneously, the hollow and porous nanotube architectures allow sufficient accessibility of exterior/interior surfaces and molecular permeability, drastically promoting the reaction kinetics. Consequently, when used as HER electrocatalysts, the well‐designed CoP/CoO PNTs show Pt‐like activity, with an overpotential of only 61 mV at 10 mA cm−2 and excellent stability in 1.0 M KOH medium, exceeding those of the vast majority of the previously reported nonprecious candidates. Density functional theory calculations further substantiate that the construction of CoP/CoO heterojunctions enables optimization of the Gibbs free energies for water adsorption and H adsorption, resulting in boosted HER intrinsic activity. The present study may provide in‐depth insights into the fundamental mechanisms of heterojunction‐induced electronic regulation, which may pave the way for the rational design of advanced Earth‐abundant electrocatalysts in the future

Interfacial engineering Co and MnO within N,S co-doped carbon hierarchical branched superstructures toward high-efficiency electrocatalytic oxygen reduction for robust Zn-air batteries

Electronic regulation via interfacial formation is identified as a versatile strategy to improve the electrocatalytic activity. Herein, we report a feasible electrospinning-pyrolysis approach for the in-situ immobilization of Co/ MnO hetero-nanoparticles onto N,S co-doped carbon nanotubes/nanofiber-integrated hierarchical branched superstructures (abbreviated as Co/MnO@N,S-C NT/CNFs hereafter). The simultaneous realization of interfacial engineering and nanocarbon hybridization renders the fabricated Co/MnO@N,S-C NT/CNFs with abundant firmly anchored active sites, modified electronic configuration, improved electric conductivity, efficient mass transport pathways, and significantly reinforced stability. Profiting from the compositional synergy and architectural advantages, the Co/MnO@N,S-C NT/CNFs exhibit outstanding ORR activity, superior tolerance to methanol, and excellent long-term stability in KOH electrolyte. More encouragingly, as a proof-of-concept demonstration, the rechargeable aqueous and flexible all-solid-state Zn-air batteries using Co/MnO@N,S-C NT/NFs + RuO2 as the air-cathode afford higher power densities, larger specific capacities and superb cycling stability, outperforming the state-of-the-art Pt/C + RuO2 counterparts. This work demonstrates the great contribution of heterointerfaces for oxygen electrocatalysis