Laser-Induced Generation of Hydrogen in Water by Using Graphene Target

Abstract

A new method of hydrogen generation from water, by irradiation with CW infrared laser diode of graphene scaffold immersed in solution, is reported. Hydrogen production was extremely efficient upon admixing NaCl into water. The efficiency of hydrogen production increased exponentially with laser power. It was shown that hydrogen production was highly efficient when the intense white light emission induced by laser irradiation of graphene foam was occurring. The mechanism of laser-induced dissociation of water is discussed. It was found that hydrogen production was extremely high, at about 80%, and assisted by a small emission of O2, CO and CO2 gases.

Laser-Induced Broadband White Emission of NdAlO3 Nanocrystals in Alcohols

“…This hot electron emission was observed in graphene foam 10 and proposed to be responsible for the dehydrogenation of ethanol producing H 2 , CH 4 , and CO in graphene, 20 and photocatalytic activity was also observed in methanol, both liquid and vapor, 18,19 as well as in water. 21 The bubbles observed in this article may also be associated with the production of gases, specially H 2 . 31 The emission spectra are presented in Figure 3.…”

“…15−17 In fact, LIWE has been used previously to produce hydrogen from methanol, 18,19 ethanol, 20 and water. 21 Although LIWE has been observed in such a wide variety of materials, usually the experimental data is obtained either in vacuum or air. 1−14 It is the first time that the nonlinear behavior of the emission is registered in liquid media, to the best of our knowledge.…”

“…Several mechanisms have been proposed for this phenomenon, such as blackbody radiation, , oxygen vacancy, multiphoton ionization, and intervalence charge transfer. ,,,, Concerning multiphoton ionization and intervalence charge transfer (IVCT) both can act synergistically, in which a multiphoton absorption is responsible for the ionization of the material, creating an intervalence pair, such as Ce 3+ -Ce 4+ , Eu 2+ -Eu 3+ , Yb 2+ -Yb 3+ , , and Cr 3+ -Cr 4+ , that can undergo an IVCT generating this broadband emission in the whole visible range. Additionally, ejection of hot electrons has been observed in LIWE, which has the potential to be used in photocatalytic applications. − In fact, LIWE has been used previously to produce hydrogen from methanol, , ethanol, and water …”

Broad Luminescence Generated by IR Laser Excitation from CsPbBr3:Yb3+ Perovskite Ceramics

“…Two main applications were linked to LIE: since it presents a high color rendering index (CRI) close to 100 [ 36 , 37 , 38 ], it is very favorable for indoor lighting applications. Furthermore, the ejection of electrons was recently linked to the production of H 2 [ 39 , 40 , 41 ], adding great value for research in laser-induced emission since it is a very active field of research for green energy generation. Additionally, LIE is capable of increasing the light power output in tungsten lamps [ 42 ], which could significantly increase interest in it.…”

Boosting the photocatalytic activity of electrolyte for higher energy efficiency in water electrolysis under influence of an optimal laser

“…Hence among many extensive efforts in hydrogen generation, the photo electrolysis i.e., electrolysis under visible light irradiation to get water splitting has shown better findings as compare to other the other methods [4,[17][18][19][20][21].…”