Improved Photo‐Excited Carriers Transportation of WS₂‐O‐Doped‐Graphene Heterostructures for Solar Steam Generation

Abstract

clean water shortages due to its minimal carbon footprint. [9][10][11][12] Photothermal material is a key component in the interfacial solar evaporation systems. Up to now, the main types of photothermal materials such as carbon-based materials, [11,13] plasmonic metal nanoparticles [14][15][16][17] and narrow band-gap semiconductors, [18] have been widely investigated for solar water evaporation.Transition metal dichalcogenides (TMDs), [19][20][21][22] hexagonal boron nitride (h-BN) [23][24][25][26] and transition carbide and nitrides [27][28][29] have been arising extensive interest in photothermal conversion and energy harvesting due to their specific chemical and physical properties. [30] Tungsten disulfide (WS 2 ) , as one of the TMDs materials, has been widely investigated in optoelectronic devices, [31] sensors, [32] energy storage and conversion, [33] and solar steam generation. [34] In addition, WS 2 semiconductor demonstrates a promising photocatalytic degradation of organic pollutants (rhodamine B: RhB) due to its narrow bandgap (1.3 eV) and low electronegative valence band, providing an excellent opportunity for both producing clean water and removing the organic pollutants via solar-driven steam generation. [35] Nevertheless, WS 2 materials exhibit short-wave solar light-absorbing, limiting its full-spectra solar energy utilization and reducing photothermal conversion efficiency. [36] Carbon materials, such as graphene, hold high full-wave solar absorption, excellent structural tunability and light-to-heat conversion efficiency, [13] which could offer a platform to adjust the photothermal capacity of WS 2 by fabricating their heterostructures. In the heterostructure system, the graphene acts as the transport pathway for the photo-excited carrier due to its high mobility and can assist exciton or electron-hole pair's dissociation for improving the photoresponse performance of WS 2 samples. [37] The fabrication of WS 2 -graphene heterostructures usually employs the chemical vapor deposition (CVD) technique or mechanical exfoliation transfer method. [37,38] Although these synthetic processes have high-level controllability, they exhibit low productivity and are only suitable for fundamental research, impeding large-scale manufacturing applications. Two-dimensional (2D) transition metal dichalcogenides and graphene have revealed promising applications in optoelectronic and energy storage and conversion. However, there are rare reports of modifying the light-to-heat transformation via preparing their heterostructures for solar steam generation. In this work, commercial WS 2 and sucrose are utilized as precursors to produce 2D WS 2 -O-doped-graphene heterostructures (WS 2 -O-graphene) for solar water evaporation. The WS 2 -O-graphene evaporators demonstrate excellent average water evaporation rate (2.11 kg m −2 h −1 ) and energy efficiency (82.2%), which are 1.3-and 1.2-fold higher than WS 2 and O-doped graphene-based evaporators, respectively. Furthermore, for the real seawater with different pH values (p...

Recent Advances of Green Electricity Generation: Potential in Solar Interfacial Evaporation System

“…[78] near-infrared regions, making them ideal candidates for photothermal applications. [79,80] For instance, multiwalled carbon nanotubes, [81] graphene (G), [82] and graphene oxide (GO) [83] have gained widespread adoption. However, the relatively high radiation coefficient of carbon-based materials can restrict their performance, necessitating the incorporation of complementary light absorbers to enhance their spectral range.…”

Advances in special wettable materials for adsorption separation of high-viscosity crude oil/water mixtures

“…Thus, the development of adsorption and separation materials with solar heating properties will certainly contribute to green and sustainable energy systems via effectively alleviating the energy and environmental crisis caused by the conventional overuse of fossil fuel heating. 115 At present, a variety of solar-heated materials have been developed, such as graphene, 116,117 carbon nanotubes, 118,119 polypyrrole, 120,121 polydopamine (PDA), 84,122 metal dichalcogenides, 123,124 metallic nanostructures, 125,126 metal oxides, 127,128 MXene, 129,130 etc. Generally, whether a photothermal adsorption separation material possesses excellent photothermal conversion ability first requires to have a broad-spectrum solar adsorption capability to adsorb as much solar energy as possible and convert it into thermal energy, thus reducing the viscosity of crude oil.…”

Evolution of Morphology and Distribution of Salt Crystals on a Photothermal Layer during Solar Interfacial Evaporation

“…Solar evaporation from seawater is driving a paradigm shift toward a more sustainable and environmentally friendly solution to the scarcity of fresh water in the world. , Solar interfacial evaporation (SIE) by leveraging localized heating on a porous photothermal framework − has been demonstrated to be highly efficient for desalination and wastewater decontamination. , In SIE, the photothermal layers, such as those with carbon , or metallic-based − materials, are placed far above the free surface of seawater to avoid heat loss from conduction to the bulk water. The heat from photothermal conversion is localized on the evaporation surface, leading to enhanced energy efficiency and evaporation rate. , A current challenge is to avoid the negative impact of salt crystallization on the long-term high evaporation rate.…”