Platinum Alloy Tailored All-Weather Solar Cells for Energy Harvesting from Sun and Rain

Self-powered PtNi-polyaniline films for converting rain energy into electricity

Developing novel rainwater energy harvesting beyond conventional electricity is a promising strategy to address the problems of the energy crisis and environmental pollution. In this current work, a class of self-powered PtNi and optimal PtNi-polyaniline (PANI) films are successfully developed to convert rainwater into electricity for power generation. The maximized current, voltage and power of the self-powered PtNi-PANI films are 4.95 μA per droplet, 69.85 μV per droplet and 416.54 pW per droplet, respectively, which are attributed to the charging/discharging electrical signals between the cations provided by the rainwater and the electrons offered by the films. These results indicate that the optimized signal values are highly dependent on the elevated electron concentration of films, as well as the concentration, radius and charge of ions in rainwater. This work provides fresh insights into rain energy and enriches our knowledge of how to convert renewable energy into electricity generation.

PANa/Covalent organic framework composites with improved water uptake and proton conductivity

It is a challenge to effectively load proton carriers in COFs to improve their proton conductivity. Herein, we report a series of COF-based composites, PANa@UCOF-x (PANa: sodium polyacrylate, x: weight percentage of PANa), which were prepared by coating different proportions of superabsorbent PANa on the COF surface based on an in situ reaction strategy. Since PANa can greatly enhance the enrichment of water molecules in one-dimensional (1D) channels of COFs, these COF-based composites exhibit superprotonic conduction. At 80 °C and 95% relative humidity (RH), the proton conductivity of PANa@UCOF-10, PANa@UCOF-28 and PANa@UCOF-40 reaches 1.6 × 10^-2, 5.1 × 10^-2, and 1.1 × 10^-1 S cm^-1, respectively, which is 4-5 orders of magnitude higher than 7.4 × 10^-7 S cm^-1 of the original UCOF. This work not only develops a new method to improve the water content of the COF channels, but also proves the important role of ordered channels in constructing effective proton conduction pathways.

Designing and Understanding the Outstanding Tri-Iodide Reduction of N-Coordinated Magnetic Metal Modified Defect-Rich Carbon Dodecahedrons in Photovoltaics

Nitrogen-coordinated metal-modified carbon is regarded as a novel frontier electrocatalyst in energy conversion devices. However, the construction of intrinsic defects in a carbon matrix remains a great challenge. Herein, N-coordinated magnetic metal (Fe, Co) modified porous carbon dodecahedrons (Fe/Co-NPCD) with a large surface area, rich intrinsic defects, and evenly distributed metal-N_x species are successfully synthesized via the rational design of iron precursor and the bimetallic-organic frameworks. Because of a synergistic effect between N-coordinated dual magnetic metal active sites, the Fe/Co-NPCD exhibits exceptional electrocatalytic activity and electrochemical stability. A solar cell fabricates with the Fe/Co-NPCD yields an impressive power conversion efficiency of 8.35% in dye-sensitized solar cells, superior to that of mono-metal-doped carbon-based cells and conventional Pt-based cells. Furthermore, density functional theory calculations illustrate that Fe, Co, and N doping are in favor of improving the adsorption capacity of the catalyst for I₃ ^- species by optimizing the magnetic momentum between the magnetic metal atoms, thereby upgrading its catalytic activity. This work develops a general strategy for synthesizing a high-performance defect-rich carbon-based catalyst, and offers valuable insight into the role of magnetic metals in catalysis, which can be used to guide the design of high-performance catalysts in the energy field.

Bioinspired Hierarchical Nanofabric Electrode for Silicon Hydrovoltaic Device with Record Power Output

Direct electricity generation from water flow/evaporation, coined hydrovoltaic effect, has recently attracted intense interest as a facile approach to harvest green energy from ubiquitous capillary water flow or evaporation. However, the current hydrovoltaic device is inferior in output power efficiency compared to other renewable energy devices. Slow water evaporation rate and inefficient charge collection at device electrodes are two fundamental drawbacks limiting energy output efficiency. Here, we report a bioinspired hierarchical porous fabric electrode that enables high water evaporation rate, efficient charge collection, and rapid charge transport in nanostructured silicon-based hydrovoltaic devices. Such an electrode can efficiently collect charges generated in nanostructured silicon as well as induce a prompt water evaporation rate. At room temperature, the device can generate an open-circuit voltage (V_oc) of 550 mV and a short-current density (J_sc) of 22 μA·cm^-2. It can output a power density over 10 μW·cm^-2, which is 3 orders of magnitude larger than all those reported for analogous hydrovoltaic devices. Our results could supply an effective strategy for the development of high-performance hydrovoltaic devices through optimizing electrode structures.

A revolution of photovoltaics: persistent electricity generation beyond solar irradiation

The integration utilization of solar energy and waste energies by photovoltaics is regarded as a promising solution to resolve energy crisis and environmental pollution problems.

Synergistically Enhanced Electrochemical Performance of Ni3S4-PtX (X = Fe, Ni) Heteronanorods as Heterogeneous Catalysts in Dye-Sensitized Solar Cells

Platinum (Pt)-based alloys are considerably promising electrocatalysts for the reduction of I^-/I₃^- and Co²⁺/Co³⁺ redox couples in dye-sensitized solar cells (DSSCs). However, it is still challenging to minimize the dosage of Pt to achieve comparable or even higher catalytic efficiency. Here, by taking full advantages of the Mott-Schottky (M-S) effect at the metal-semiconductor interface, we successfully strategize a low-Pt-based M-S catalyst with enhanced electrocatalytic performance and stability for the large-scale application of DSSCs. The optimized M-S electrocatalyst of Ni₃S₄-Pt₂X₁ (X = Fe, Ni) heteronanorods is constructed by rationally controlling the ratio of Pt to transition metal in the hybrids. It was found that the electrons transferred from Ni₃S₄ to Pt₂X₁ at their interface under the Mott-Schottky effect result in the concentration of electrons onto Pt₂X₁ domains, which subsequently accelerates the regeneration of both I^-/I₃^- and Co²⁺/Co³⁺ redox shuttles in DSSCs. As a result, the DSSC with Ni₃S₄-Pt₂Fe₁ manifests an impressive power conversion efficiency (PCE) of 8.79% and 5.56% for iodine and cobalt-based electrolyte under AM1.5G illumination, respectively. These PCEs are obviously superior over those with Ni₃S₄-Pt, PtFe, Ni₃S₄, and pristine Pt electrodes. The strategy reported here is able to be further expanded to fabricate other low-Pt-alloyed M-S catalysts for wider applications in the fields of photocatalysis, water splitting, and heterojunction solar cells.

A long persistence phosphor tailored quasi-solid-state dye-sensitized solar cell that generates electricity in sunny and dark weathers

An all-weather quasi-solid-state dye-sensitized solar cell is built using a long persistence phosphor tailored mesoscopic TiO₂ photoanode and a three-dimensional conducting polymer gel electrolyte. The so-called all-weather solar cell yields a maximum efficiency of 28.7% in the dark, making a promising photovoltaic revolutionary for state-of-the-art photovoltaics.

Extra-high short-circuit current for bifacial solar cells in sunny and dark–light conditions

We present here a symmetrically structured bifacial solar cell tailored by two fluorescent photoanodes and a platinum/titanium/platinum counter electrode, yielding extra-high short-circuit current densities as high as 28.59 mA cm⁻² and 119.9 μA cm⁻² under simulated sunlight irradiation (100 mW cm⁻², AM1.5) and dark–light conditions, respectively.