Carbon-incorporated porous honeycomb NiCoFe phosphide nanospheres were successfully prepared, exhibiting excellent performance for overall water splitting.

Porous carbon and metal oxides/sulfides prepared by using metal–organic frameworks (MOFs) as the precursors have been widely applied to the realm of supercapacitors. However, employing MOF‐derived metal phosphides as positive and negative electrode materials for supercapacitors has scarcely been reported thus far. Herein, two types of MOFs are used as the precursors to prepare CoP and FeP4 nanocubes through a two‐step controllable heat treatment process. Due to the advantages of composition and structure, the specific capacitances of FeP4 and CoP nanocubes reach 345 and 600 F g−1 at the current density of 1 A g−1, respectively. Moreover, a quasi‐solid‐state asymmetric supercapacitor is assembled based on charge matching principle by employing CoP and FeP4 nanocubes as the positive and negative electrodes, respectively, which exhibits a high energy density of 46.38 Wh kg−1 at the power density of 695 W kg−1. Furthermore, a solar‐charging power system is assembled by combining the quasi‐solid‐state asymmetric supercapacitor and monocrystalline silicon plates, substantiating that the device can power the toy electric fan. This work paves a practical way toward the rational design of quasi‐solid‐state asymmetry supercapacitors systems affording favorable energy density and long lifespan.

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Metal-organic frameworks (MOFs) as an emerging kind of poriferous crystalline compounded material, the preparation and applications including gas storage, [1,2] catalysis, [3] separation, [4] drug delivery, [5,6] and chemical sensors [7] of its new porous structure has achieved tremendous development in the past few decades. Co8-MOF-5 was first reported as electrode materials for supercapacitors (SCs). MOFs with large specific surface area attribute to high rate of holes that can reserve ample electric charge and promote the dispersion of electrolyte ions as well as provide plentiful faradaic redox centers. [8] Therefore, more and more MOFs used as electrode materials have been rapidly developed. It was Yang et al. first published that a 2D nickel-based MOF has excellent current capability (providing a high specific volume of 1127 F g À1 at 0.5 A g À1 ) and outstanding cycle durability (over 90% capacitance retention after cycling 3000 times). [9] The synthesis of unique flower-like structure Ni-MOFs has been reported, which produced a high pseudo capacity of 1457.7 F g À1 at 1 A g À1 . [10] However, currently, most Ni-MOFs with high capability and unique morphology are synthesized by solvothermal method. On various occasions, solvothermal requires a long reaction time of up to several days. Moreover, the reaction of the frame members must be carried out at high temperatures (usually 373-523 K) and pressure (1-10 MPa). Considering the great capability of MOFs to be used in SCs in the future, some more effective and new synthesis techniques for substitution should be developed as soon as possible. What is more, the adoption of high-duty ultrasound (US) can provide a convenient, environmental, and commonly used compositing tool for MOFs materials.US causes chemical changes based on cavitation phenomena, involving the sequential generation, rising, and succedent collapse of bubbles in hot spots. [11][12][13] More specifically, when radiated by the US, the alternating expansion sound wave and compression sound wave will produce bubbles, and the vibratory blisters can amass US power to a particular amount (tens of millimeters). The bubbles will grow excessively in a very short life (heating and cooling rates > 1010 K s À1 ) and then collapse. [14][15][16] A great concentration of energy was obtained in the course of the eruption, bringing a certain temperature at a certain part of about 5000 K and a pressure of about 1000 bar. This power will be diffused into the surroundings during the collapsing, so the temperature of the gas at the important point will quickly renew to the value of the surroundings and its rates of heating/cooling will return to up 1010 K s À1 . [17] Because of such factors, US irradiation make it possible to get sufficient amounts of energy to achieve the reaction which is previously hard to get with other approaches. even macroscopically at room temperature. In detail, the first synthesis material came into being in 2008 by Qiu et al. with (Zn 3 BTC 2 12H 2 O). [18]

Upconversion fluorescence (NaYF 4 /Yb, Er) is a promising technique employed by solar cells for enhancing light harvesting, especially for manipulating the lowenergy photons. Here, we report a semiconductor/NaYF 4 /Yb, Er hybrid structure applied to photoelectrochemical (PEC) water oxidation. Three emission peaks in visible wavelengths at 522.5, 541.5, and 655.5 nm are observed for NaYF 4 /Yb, Er under 980 nm excitation due to a nonlinear anti-Stokes process. Owing to the overlap between the upconversion fluorescent emission of NaYF 4 /Yb, Er and the UV−vis absorption edge of Fe 2 O 3 , the hybrid structure Fe 2 O 3 /NaYF 4 /Yb, Er presents 70% enhancement of the photocurrent density compared with the pristine Fe 2 O 3 and 19% improvement in the carrier concentration. The charge-transfer kinetics at the electrode/electrolyte interface is also reinforced. Through the radiationreabsorption mechanism, this hybrid semiconductor integrated with upconversion fluorescence reveals efficient energy conversion effect and presents valuable reference for PEC applications.