The free enzyme has a 27 % higher initial product formation rate and therefore also a higher H2O2 efficiency (see SI for H2O2 production data) indicating kinetic limitations of the immobilized enzyme. The H2O2 efficiency can be expressed as the quotient of the product formation rate in the photobiocatalytic system, and the rate of H2O2 produced in the system measured without enzyme (EFF of H2O2=rproduct/rH2O2).