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Photo-induced H2 production from a CH3OH-H2O solution at insulator surface.

Li R, Wang X, Jin S, Zhou X, Feng Z, Li Z, Shi J, Zhang Q, Li C - Sci Rep (2015)

Bottom Line: However, in this work, we found that a considerable amount of H2 can be generated from a CH3OH-H2O solution at a quartz surface using light with energy far outside the electronic absorbance range of the CH3OH-H2O solution; this process should not occur in principle via either conventional photocatalysis or a photochemical process.The H2 production was further confirmed using 266 nm and 355 nm lasers as light sources.Our work demonstrates that photo-induced H2 production can occur on insulator surfaces (e.g., quartz), which were commonly believed to be inert, and will shed light on the surface nature of insulators.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China.

ABSTRACT
In a conventional photocatalytic or photochemical process, either a photocatalyst or a molecule is excited by irradiation light that has energy greater than the forbidden band (i.e., the band gap) of the semiconductor or the transition energy of an excited state of the molecule, respectively, for a reaction to occur. However, in this work, we found that a considerable amount of H2 can be generated from a CH3OH-H2O solution at a quartz surface using light with energy far outside the electronic absorbance range of the CH3OH-H2O solution; this process should not occur in principle via either conventional photocatalysis or a photochemical process. The H2 production was further confirmed using 266 nm and 355 nm lasers as light sources. Our work demonstrates that photo-induced H2 production can occur on insulator surfaces (e.g., quartz), which were commonly believed to be inert, and will shed light on the surface nature of insulators.

No MeSH data available.


Related in: MedlinePlus

(a) The configuration of reactor used in the experiment; (b) photo-induced H2 production from a CH3OH-H2O solution without photocatalyst under the light irradiation; (c) The concentration dependence of the H2 production from the CH3OH-H2O solution; (d) The pH dependence of the H2 production from the CH3OH-H2O solution, the pH value of solution was adjusted with H2SO4 or NaOH solution (1.0 mol/L). Reaction condition: 500 mL CH3OH-H2O solution, the concentration of CH3OH was 10% in volume in (b,d); 450 W high-pressure Hg lamp; Pure CH3OH (>99.99%) and pure water (18 MΩ H2O, obtained from a Milli-Q water purification system) was used in the experiment.
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f1: (a) The configuration of reactor used in the experiment; (b) photo-induced H2 production from a CH3OH-H2O solution without photocatalyst under the light irradiation; (c) The concentration dependence of the H2 production from the CH3OH-H2O solution; (d) The pH dependence of the H2 production from the CH3OH-H2O solution, the pH value of solution was adjusted with H2SO4 or NaOH solution (1.0 mol/L). Reaction condition: 500 mL CH3OH-H2O solution, the concentration of CH3OH was 10% in volume in (b,d); 450 W high-pressure Hg lamp; Pure CH3OH (>99.99%) and pure water (18 MΩ H2O, obtained from a Milli-Q water purification system) was used in the experiment.

Mentions: The experiment was conducted using the typical widely-used setup for evaluating photocatalytic H2 production but without the addition of any photocatalyst. A high-pressure Hg lamp was employed as the light source; this type of source has commonly been used to evaluate semiconductor-based photocatalysts (Figure S1). The Hg lamp is located inside the reactor so that the light can pass through the reactor wall to the CH3OH-H2O solution (Fig. 1a and Figure S2). To obtain the required range of light source, different light-absorbing solutions are filled in the filter layer (quartz-made) to filter the light by absorbing a specific range of light. After the reaction, the produced gas fills a glass-made closed system and is connected to a gas chromatography (GC) apparatus for analysis.


Photo-induced H2 production from a CH3OH-H2O solution at insulator surface.

Li R, Wang X, Jin S, Zhou X, Feng Z, Li Z, Shi J, Zhang Q, Li C - Sci Rep (2015)

(a) The configuration of reactor used in the experiment; (b) photo-induced H2 production from a CH3OH-H2O solution without photocatalyst under the light irradiation; (c) The concentration dependence of the H2 production from the CH3OH-H2O solution; (d) The pH dependence of the H2 production from the CH3OH-H2O solution, the pH value of solution was adjusted with H2SO4 or NaOH solution (1.0 mol/L). Reaction condition: 500 mL CH3OH-H2O solution, the concentration of CH3OH was 10% in volume in (b,d); 450 W high-pressure Hg lamp; Pure CH3OH (>99.99%) and pure water (18 MΩ H2O, obtained from a Milli-Q water purification system) was used in the experiment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4551957&req=5

f1: (a) The configuration of reactor used in the experiment; (b) photo-induced H2 production from a CH3OH-H2O solution without photocatalyst under the light irradiation; (c) The concentration dependence of the H2 production from the CH3OH-H2O solution; (d) The pH dependence of the H2 production from the CH3OH-H2O solution, the pH value of solution was adjusted with H2SO4 or NaOH solution (1.0 mol/L). Reaction condition: 500 mL CH3OH-H2O solution, the concentration of CH3OH was 10% in volume in (b,d); 450 W high-pressure Hg lamp; Pure CH3OH (>99.99%) and pure water (18 MΩ H2O, obtained from a Milli-Q water purification system) was used in the experiment.
Mentions: The experiment was conducted using the typical widely-used setup for evaluating photocatalytic H2 production but without the addition of any photocatalyst. A high-pressure Hg lamp was employed as the light source; this type of source has commonly been used to evaluate semiconductor-based photocatalysts (Figure S1). The Hg lamp is located inside the reactor so that the light can pass through the reactor wall to the CH3OH-H2O solution (Fig. 1a and Figure S2). To obtain the required range of light source, different light-absorbing solutions are filled in the filter layer (quartz-made) to filter the light by absorbing a specific range of light. After the reaction, the produced gas fills a glass-made closed system and is connected to a gas chromatography (GC) apparatus for analysis.

Bottom Line: However, in this work, we found that a considerable amount of H2 can be generated from a CH3OH-H2O solution at a quartz surface using light with energy far outside the electronic absorbance range of the CH3OH-H2O solution; this process should not occur in principle via either conventional photocatalysis or a photochemical process.The H2 production was further confirmed using 266 nm and 355 nm lasers as light sources.Our work demonstrates that photo-induced H2 production can occur on insulator surfaces (e.g., quartz), which were commonly believed to be inert, and will shed light on the surface nature of insulators.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China.

ABSTRACT
In a conventional photocatalytic or photochemical process, either a photocatalyst or a molecule is excited by irradiation light that has energy greater than the forbidden band (i.e., the band gap) of the semiconductor or the transition energy of an excited state of the molecule, respectively, for a reaction to occur. However, in this work, we found that a considerable amount of H2 can be generated from a CH3OH-H2O solution at a quartz surface using light with energy far outside the electronic absorbance range of the CH3OH-H2O solution; this process should not occur in principle via either conventional photocatalysis or a photochemical process. The H2 production was further confirmed using 266 nm and 355 nm lasers as light sources. Our work demonstrates that photo-induced H2 production can occur on insulator surfaces (e.g., quartz), which were commonly believed to be inert, and will shed light on the surface nature of insulators.

No MeSH data available.


Related in: MedlinePlus