A Simple, Scalable, Low‐Cost Honeycomb‐Like Carbonized Corncob for Highly Efficient Solar Steam Generation

Abstract

Direct solar steam generation (DSSG) is currently one of the most promising desalination methods due to its high energy conversion efficiency. The key element of DSSG is solar thermal conversion materials (STCMs), which absorb incoming solar illumination owing to their excellent solar absorption and convert light to heat. Although many types of STCMs have been applied to DSSG, there are still some existing problems such as complex preparation, high cost, and low energy conversion efficiency. In this work, carbonized corncob, as an example of inexpensive agricultural waste, is prepared as a STCM, which has porous honeycomb‐like pores, and hydrophilic functional groups, ensuring sufficient water transportation. Different pyrolytic temperatures lead to different size pores, content of amorphous carbon, and amount of oxygen functional groups, which affect the water transportation efficiency and light‐to‐heat conversion efficiency. Benefiting from developed pores, 95.7% solar absorption and thick‐hole wall, the carbonized corncob pyrolyzed at 800 °C reaches a solar‐to‐steam conversion efficiency of 86%, and its water evaporation rate is 1.62 kg m–2 h–1, higher than most biomass reported so far. Using cost‐effective materials and methods to carry out efficient photothermal conversion is of great significance for the realization of practical seawater desalination and sewage treatment.

Highly Effective Multifunctional Solar Evaporator with Scaffolding Structured Carbonized Wood and Biohydrogel

“…A potential solution is to use the micro- or nano-structure of natural materials as the basis to build the framework structure. Thus, carbonized wood (CW) has attracted a great deal attention due to its advantages including solar energy absorption and photothermal conversion properties, renewability, low cost, environmental friendliness, and natural channel structures for water transportation. − Most reported common CW with a through-hole structure faces challenges such as a limited surface area and salt crystal blockage in channels, which will lead to a significant decrease in water transportation rate. , Some species of wood have special microstructures; for example, Melaleuca Leucadendron L. has a loose and ordered scaffolding microstructure, being significantly different from that of the reported CW. Because of the larger surface area and topological form of its scaffolding structure, the carbonized M.…”

Semicarbonized Subwavelength-Nanopore-Structured Nanocellulose Paper for Applications in Solar Thermal Heating

“…According to the statistical analysis, the solar absorption of the nanopaper carbonized at 500 °C was significantly different from those of the nanopapers carbonized at 300, 400, and 600–1100 °C ( p -value: ≤0.038). The solar absorption of the nanopaper carbonized at 500 °C (96.7%) was superior to those of various carbonized biomass materials, such as carbonized mushroom (96%), carbonized corncob (95.7%), and arched bamboo charcoal (94.1%) . Regardless of the carbonization temperature, the carbonized nanopapers exhibited almost no photoluminescence, indicating that most of the solar light absorbed by the carbonized nanopaper had been converted to heat (Figure S5).…”

Systematic Review of Material and Structural Design in Interfacial Solar Evaporators for Clean Water Production

“…Carbonized polymers are becoming one kind of popular materials in the design of interfacial solar evaporators, which could be mainly classified into two categories based on their sources: carbonized natural polymers such as woods, [11,167] fruits, [168] and corncobs [169] and carbonized chemical polymers such as MOFs [65,[170][171][172][173] and poly(ethylene terephthalate) (PET). [174] Normally, the typical carbonized process is achieved under inert gas atmosphere such as nitrogen and argon at high temperature.…”

“…[174] Normally, the typical carbonized process is achieved under inert gas atmosphere such as nitrogen and argon at high temperature. [169,170,173,175] Still, some other carbonization methods are arising recently, including, using alcohol lamps and hot plates directly, [167,176] as well as hydrothermal carbonization even with templates and catalysts. [168,174,177] The detailed information, including materials, carbonization conditions, and performance of interfacial solar evaporation, is given in Table 5.…”