Table 3 Estimated costs involved in the synthesis of 1% Cu-doped BiVO₄.

Raw materials

 Bi(NO₃)₃·5H₂O

3.3954 g

RM 2.38/g

Bi source

 NH₄VO₃

0.8189 g

RM 1.25/g

V source

 CuSO₄·5H₂O

0.101 g

RM 2.75/g

Cu dopant source

 Total raw material cost

Synthesis process

 Hydrothermal heating (180 °C)

1.5 kWh × 15 h = 22.5 kWh

RM 0.24 per kWh*

Energy cost for autoclave operation

 Deionized water

200 mL

RM 0.01/mL

For dissolving reagents and washing catalyst

 Ethanol (for washing)

20 mL

RM 0.11/mL

For catalyst washing

 Drying

1.5 kWh × 12 h = 18.0 kWh

RM 0.24 per kWh*

Energy cost for oven operation

 Calcination

3.0 kWh × 4 h = 12.0 kWh

RM 0.24 per kWh*

Energy cost for box furnace operation

 Total synthesis cost

Equipment depreciation

 Teflon-lined autoclave usage

–

–

Based on estimated equipment depreciation per batch

 Centrifuge/filtration setup

–

–

Equipment for recovery and filtration

 Total equipment cost

Overall cost

Per batch (3.5 g photocatalyst yield)