Catalyst for Formic acid decomposition
In A Novel Example of Molecular Hydrogen Generation from Formic Acid at
Visible-Light-Responsive Photocatalyst, the authors describe the formation of carbon dioxide and hydrogen from formic acid using visible light from a halogen lamp and freshly prepared $\ce{Cu2O}$ (or platinum-covered $\ce{Cu2O}$) as a catalyst.

The preparation of the $\ce{Cu2O}$ is described as follows:


  Ten cubic centimeters of $\mathrm{1.0~mol~dm^{-3}}$
  $\ce{CuSO4*9H2O}$ aqueous solution was dropped
  into $\mathrm{100~cm^3}$ of $\mathrm{1.0~mol~dm^{-3}}$ $\ce{Na2S2O3}$ aqueous solution, and
  subsequently, the mixture solution was dropped into $\mathrm{200~cm^3}$
  of $\mathrm{1.0~mol~dm^{-3}}$ $\ce{NaOH}$ solution at 80 °C. 
  
  The resulting reddish-brown precipitate ($\ce{Cu2O}$) was separated by filtration and washed with deionized water, after which the precipitation was dried at 40 °C in an $\ce{Ar}$ atmosphere.


The conversion of formic acid is described as follows:


  The photocatalytic experiment was conducted in a glass vessel (volume: $\mathrm{20~cm^3}$) containing $\mathrm{10~cm^3}$ of $\mathrm{2.5~mol~dm^{-3}}$ $\ce{HCOOH}$ and a known amount of photocatalyst (10 mg (ca. 70 μmol)) [...] in
  $\ce{Ar}$ atmosphere with stirring. The pH of the $\ce{HCOOH}$ solution was adjusted to 5.0 by the addition of $\ce{NaOH}$ solution. 
  
  A halogen lamp was used as the light source (light intensity: $\mathrm{280~mW~cm^{-2}}$ ) along with a sharp-cut filter (S76-L42, Suruga Seiki Co. Ltd.), using which the samples were irradiated with light of wavelength $\lambda &gt; 420~\mathrm{nm}$. [...] 


In summary, it seems possible to perform the experiment at school. UV filters are available from different manufacturers, a Schott N-WG320 might work.