Perpustakaan Digital ITB

Photocatalytic water splitting or CO2reduction is one of the mostpromising strategies for solar energy conversion into hydrogen-containing fuels.However, these two processes typically compete with each other, which significantlydecreases the solar energy conversion efficiency. Herein, we report for thefirst time thiscompetition can be overcome by modulation of reactive sites and electron transferpathway of heterogeneous photocatalysts. As a prototype, BiO composite reducedgraphene oxide quantum dots (RGO-BiO QDs) were synthesized, which can providelarge amounts of photogenerated electrons as well as individual reactive sites for H+andCO2reduction. The productivity of H2,CH4, and CO by the RGO-BiO QDs catalystwere 102.5, 21.75, and 4.5?mol/(g·h), respectively, in pure water without theassistance of any cocatalyst or sacrificial agent. The apparent quantum efficiency at 300nm reached to 4.2%, which is more than 10 times higher than that of RGO-TiO2QDs(0.28%) under the same conditions.In situDRIFT, ESR, and photoelectrochemicalstudies confirmed that the unique circled electron transfer pathway (Evb(BiO)?Ecb(BiO)?Ef(RGO)?EVo•(BiO)) and thelarge amount of separated different reactive sites are responsible for the highly efficient simultaneous H2evolution and CO2reduction performance